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Central Heating Problems

Does what it says on the tin
Bouleversee
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Re: Central Heating Problems

#489208

Postby Bouleversee » March 25th, 2022, 5:36 pm

88V8 wrote:
Bouleversee wrote:Well, that was yesterday afternoon and maybe they weren't thawed by the time they left though the pipes are very thin but he should have known that.
All the other rads got hot but now none of them are because the boiler is not igniting. I did ask him if had checked the tank and the ballcock and he said yes. I don't see any evidence of an overflow dripping outside. Come to think of it, I think they may have had a couple of buckets with them. I wish I had watched what they were doing.

Pipes will have thawed in a couple of hours.

Buckets... when changing the valves they will have had to drain the rads. That water should then have been put back into the system via the header tank.
Should have.

Overflow... no...
The question is whether there's any water at all in the tank... not whether there's too much.
And whether the valve from the tank to the system is turned on, as it should be.

When freezing, they will likely have turned off the lockshield valves... the ones at the opposite end of the rad. I suppose they turned them back on? That would stop the rads heating although you would still be able to bleed water out.
If they are on, don't disturb the setting as those valves are used to balance the system, and they should have been re-opened to the exact same extent as they were before.

If the house is well insulated, can leave heating on all day. If not well insulated, let it go off during the day.

V8


The rads whose pipes were frozen and trvs replaced are not the ones which were not getting hot and seem to lack water; those are on the floor above. I agree that any water removed from rads should be replaced in the header tank which the certainly didn't do (he only looked for it when he found the upstairs rads weren't heating and didn't have enough/any water. How long should they take to fill with a small bore pipe system? Perhaps I should have given it longer but I couldn't hear anything happening. I had asked him to check whether there was sufficient inhibitor in the system but he didn't. Is there a test for this?

He has just phoned me finally and is going to ring later to make an appt. to come on Monday. Thinks there may be a blockage in the pipework and asked me how long it is since it was drained down. No idea. He thinks I ought to have a sealed system as the one at the other end of the house is apparently.

As regards the overflow, I just wondered whether a blockage might have caused a build up in the tank because it couldn't get to the rads. causing an overflow but I accept what you say. If the tank is full, doesn't that indicated a blockage somewhere? I wonder if they did monitor the settings of the lockshield valves. They certainly didn't go round the circuit checking the return temp. was the same on all once the system had got up to temperature.
I think I should have been left a leaflet about the new valves. I find it hard to read that tiny grey print on my laptop. I did make this out, however:
An automatic differential bi-pass valve must be fitted in conjunction with all TRV systems. No idea whether that has been done.

Chris: I'll contact your chap if my engineer(s) don't sort it out on Monday or propose something new and expensive. Might have a word with him before then.

kiloran
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Re: Central Heating Problems

#489210

Postby kiloran » March 25th, 2022, 5:50 pm

Bouleversee wrote:
Chris: I'll contact your chap if my engineer(s) don't sort it out on Monday or propose something new and expensive. Might have a word with him before then.

I'm not convinced you've twigged who "Chris's chap" is :)

Hint: his name is Mike and is well known in these parts

--kiloran

88V8
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Re: Central Heating Problems

#489234

Postby 88V8 » March 25th, 2022, 8:24 pm

Bouleversee wrote:The rads whose pipes were frozen and trvs replaced are not the ones which were not getting hot and seem to lack water; those are on the floor above.

If the tank is full doesn't that indicate a blockage?

He thinks I ought to have a sealed system.

An automatic differential bi-pass valve must be fitted in conjunction with all TRV systems. No idea whether that has been done.

The tank should always be full.
If the upstairs has no water I am suspicious that the tank is empty or has been isolated from the system.
Someone needs to look, as I mentioned before.

The sealed system, which comes with its own problems, is the norm when there is little height for a header tank. But with a properly designed system - the correct relationship of pump and feed and vent - a header tank is perfectly possible. The problem is exacerbated in your case by the smallbore piping, which necessitates a high pump pressure to get the water around the system.

The bypass valve is to prevent the system being dead-ended when all the trvs close, as this can/will result in 'pumping over' which you really really do not want.
Another way of preventing that problem is to have one rad with no trv so there will always be somewhere for the water to go, but then you would need a room stat in that room, otherwise the system may not switch off.

Inhibitor concentration check https://www.sentinelprotects.com/uk/support/how-check-x100-inhibitor-levels

There are a lot of cowboys and incompetents in the building trade.
I am thankful that I have spent 47 years learning how to do nearly everything myself.
Although I have no doubt missed out on some wine women and song.

V8

UncleEbenezer
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Re: Central Heating Problems

#489244

Postby UncleEbenezer » March 25th, 2022, 9:45 pm

csearle wrote:
Bouleversee wrote:...
Lorna, have you tried this guy. He is about one hour(ish) away from you but would probably be happy to help so long as you accepted he'd charge for travel to/from his home? One thing you could be assured of is that he would be very straightforward with his advice. C.

Oooh. Interesting revelation there.

Too far away from me, but I might have a job for that guy on behalf of my dad, who has been struggling to find someone since finding his overpriced service contract with BG didn't cover him when he needed a fix.

Bouleversee
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Re: Central Heating Problems

#489651

Postby Bouleversee » March 28th, 2022, 12:01 am

My son went into the eaves cupboard and established that there was water in the expansion tank (about one third full (which my heating chap says is normal) and that the stopcock released water when pressed.

The heating engineer rang today to fix an appt. for a return visit on Monday. He said that his colleague who replaced the valves in my bedroom drained the water out of the radiators by means of some suction device so he couldn't see what colour it was and using this meant the water couldn't be replaced in the system. He's still on about a sealed system where pressure would force the water into the rads.

By strange coincidence, going through some pages I had cut out of newspapers to read later but hadn't done till now, there was a q & a from Home Help in the Sun. Times a while ago which said "My radiators no longer get warm. The plumber says they are clogged because air got into pipework after a leak. He wants to detach every radiator, take it into the garden and flush it out, but some rads. cannot readily be accessed and he does not want to do a partial job. What can I do?"

The answer starts: "When tap water is added to a central heating system, an inhibitor should also be added to prevent corrosion and rust forming which settles as dark sludge aka magnetite which solidifies and can block pipework". ( At the outset, I asked my plumber to test whether the inhibitor level was OK but even the draining of the rads meant that fresh water would be taken in, he hadn't done so or added any inhibitor. Incidentally, he says he doesn't use Fernox; is it OK to mix makes?) The respondent went on to say that a Fernox water sample test should be done and that a thermal image camera can also build-up. If the top corners of radiators get warm this indicates the system isn't completely blocked and maintenance is an option, i.e. power flushing with a chemical solution. As the chemicals break down the magnetite, it flows through and is removed with a magnetic filter. At the end of the process the system is topped up with water and the correct dose of inhibitor. However, he goes on to say that it doesn't always work and is likely not to work with microbore pipes, which is what I have. He says that if using a hose is the only option, try removing one rad. first to determine potential success across the whole system. ( I have to say I can't see what this would achieve if the blockage is in the tiny pipes rather than in the rads.) He concludes by saying that once the system has been cleaned, a magnetic filter should be added to the system and checked every year. (One would think that such filters should always be added to a small bore system at installation. Where would they be fitted, if they were) .

My engineer has asked me when the system was last drained and I said I didn't know (certainly not since May 2008 when I moved here) but what good would just draining do if rust had settled on the rads or pipes? All I know is that all the rads got fully hot from top to bottom before he did any work and that he didn't do any survey or investigate the humming noise which had started recently and was the main reason for calling him in. I don't know how to handle the situation tomorrow. He's already billed me almost £300 and I don't want to give him carte blanche to do whatever he feels inclined to do for an unknown figure. If the boiler (Potterton prima) has stopped firing, can it be fixed or has it had it? (Installed in Nov. 2003). Perhaps Mike could advise on that. Having had only 4 hrs sleep last night and lost another hour with the time change, I need to retire, with the hope that there will be more good advice on here before 12 Noon tomorrow when he is due to arrive, though is not always punctual.

Mike4
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Re: Central Heating Problems

#489665

Postby Mike4 » March 28th, 2022, 3:18 am

Heating engineers who install stuff as their main line of business tend not to be quite so good at diagnosing a system that won't work in my experience. They typically waffle on about air locks or rust, corrosion deposits, filters, blockages and the need for powerflushing, rads to be removed and hosed out and all such voodoo things. This can generally be translated into "We don't know why it doesn't work". Find yourself someone who fixes these things for a living though and there is a tendency for them to home in instantly on the cause and just fix it.

I've already mentioned what it sounds like to me. From your previous post I think your cold fill pipe connecting the header tank (feed and expansion tank) to the heating system proper is blocked. I could be wrong but this is a really common problem on systems of the vintage of yours I encounter several times a year. Symptoms are identical to yours and the blockage if I'm right, will be at the tee piece where the lower end of the cold fill pipe joins the heating system proper.

This can be diagnosed definitively by opening a drain cock on the system and running off a few litres of water, then rushing up to the loft to inspect the header tank to see if the float valve is running to replace the water just drained off. If it isn't running, then the diagnosis is confirmed. If it IS running, the diagnosis is wrong and can be ruled out. I suggest asking your engineer tomorrow to carry out this test specifically.

Regarding your Prima this is a very basic boiler, easily fixed and all the commonly failing parts are still available despite what certain large firms who drive blue vans might tell you ;) I suspect yours might be in good working order though, and it appears not to fire because it has heated itself up and then turned itself OFF. It will do this in the absence of circulation as the heat it generates is not being carried away to the radiators, and it has therefore turned itself OFF because it is fully up to temperature.

Is the front panel hot if you feel it? (When the heating controls are set to ON but the rads are not actually heating up?) If it isn't, then the overheat protection button may have popped out and needs pressing back in, as explained in detail on this web page linked below. (The Potterton Prima is closely related to the Potterton Profile and has the exact same overheat thermostat described.)

https://netaheat-repairs.co.uk/potterto ... oiler.html

Bouleversee
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Re: Central Heating Problems

#489702

Postby Bouleversee » March 28th, 2022, 9:42 am

Many thanks, Mike. I have printed your post and will reread it until it is all in my head and can discuss it with the engineer.

As previously mentioned, the boiler came on after they had replaced the valves, though those upstairs rads only got hot on the very bottom bit, the others did get hot throughout. It was agreed that I would turn the heating off, wait a while and then bleed those 2 rads and also the towel rail in the ground floor bathroom which had been making a bit of a racket. I did that though the upper rads never filled and when I turned the heating back on, I don't think the boiler ever ignited. As you suggest, maybe the overheat button may have popped out. I will reread your linked article and go into the garage and see if I can ascertain this though I don't want to touch anything before the engineer arrives around 12. The heating is set to off at present but I will turn it on before looking at the boiler. My guess is that it will not come on at all. I note your comment somewhere in that Netaheat article that the boiler may be caput and need replacing. I hope that won't be the case though it is time for a service. I'd like to wait a while to see what develops on the boiler front and the availability of hydrogen in the next year or two.

One thing I wanted to ask you: someone posted on here that the expansion tank should be full whereas my engineer says it should be only a third full to allow for expansion. Which is correct? My engineer keeps harping on about he doesn't know how it could ever have worked since the expansion tank (which is in an eaves cupboard on the same floor as the rads which aren't filling in my office over the garage) is not high enough in relation to those 2 rads; all over rads on that system are on the floor below. What are your view on that situation? The fact is that those 2 rads heated fully from top to bottom and the only problem I had since moving here in 2008 was that some of the trvs didn't turn off at the setting they were on and I didn't need my bedroom blaring at a high temperature all day and also that a week or so ago I noticed a humming noise which hadn't been there before. I think it might have made more sense to have investigated that before embarking on the valve changes.

I seem to remember sending you a PM quite a while ago and your saying I was too far away for you. I am near Beaconsfield, Bucks. When you service a boiler do you check the whole system or just the boiler? It would seem to me that, particularly with microbore pipework, the inhibitor status should be routinely checked but I am not aware that anyone has done anything other than look at the boiler at any annual service I have had on my boilers previously. What is the going rate for a boiler service at present?

Many thanks again to you and other contributors on here. It is not easy to cope with such issues at my age and with IPF. Incidentally, neithrr of the chaps who came last week were wearing masks which is why I tried to keep away from them. It is quite a while since I had my booster and will not be having the latest booster till Wednesday. It would probably be fatal if I caught Covid with my lung disease. My sister caught it when she was in hospital for something else in January and died.

P.S. I am absolutely freezing typing this without any heating! Perhaps I'll warm up with some breakfast. Often don't have time to eat these day.

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Re: Central Heating Problems

#489711

Postby 88V8 » March 28th, 2022, 10:27 am

Bouleversee wrote:... someone posted on here that the expansion tank should be full whereas my engineer says it should be only a third full to allow for expansion. Which is correct?

My engineer keeps harping on about he doesn't know how it could ever have worked since the expansion tank (which is in an eaves cupboard on the same floor as the rads which aren't filling in my office over the garage) is not high enough in relation to those 2 rads; all other rads on that system are on the floor below. What are your view on that situation? The fact is that those 2 rads heated fully from top to bottom...


The someone was me. What I meant is that it should have water in it, rather than none.
A third to half full is fine.

The expansion tank is the top of the system. So long as it's higher than the rads, it will work. Even if it's just a foot higher.

If rads do not heat at the top, they have air in them.
The air cannot be bled out if there's no water coming in. You've established that there is water in the tank, so that brings you back to Mike's point about a blockage being the first thing to look for.

When the engineer comes, explain about your health issues & your sister and ask/tell him to wear a mask.

V8

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Re: Central Heating Problems

#489726

Postby Bouleversee » March 28th, 2022, 11:37 am

Yes, it does sound as though there may be a blockage there but I'm not clear as to how that can be cleared (any clues?) or whether it is their actions which have caused it and whether they are entitled to charge me a whole lot extra on top of the £300 if they have caused it.

The top of the rads in my office is 28.5 inches from the floor; the bottom of the expansion tank in the eaves cupboard on the opposite side of the office is approx. 45.5 inches from the floor and it is approx. 13" high so should be ok according to you so he can't blame the system and insist on installing a sealed system, can he?

I won't waste any more of my precious time trying to bleed air out of these 2 rads, then. I wonder if there is a chance that a bit of ice blocked the narrow pipe initially and then the boiler overheat button came into play. I doubt it was 2 hrs since they had stopped freezing the pipes. Am about to go into the garage and have a look. I wonder why they used my loopaper instead of the foam sleeves.

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Re: Central Heating Problems

#489738

Postby Bouleversee » March 28th, 2022, 12:39 pm

So I went into the garage and saw the hole for the restart button and pressed it and it clicked so I went back inside and turned on the heating and sure enough the heating started to come on. I noticed that one of the office rads had was getting warm all the way up. The other was still stone cold though I checked that the trv was set to max. So I thought I'd turn off the heating and have another go at bleeding that and went back to the garage to make sure the pump had stopped running. It had but to my surprise the grey section of the boiler case had partially come off and was hanging by the knob as though there had been an explosion. There has always been a bit of a bang when starting up. So I shall have another go at bleeding the cold rad while I await the engineer who was supposed to have been here at 12. Not sure when I'll get any lunch.

Edit: a bit of air came out but no water. What is interesting is that the other rad in the office, which had got fairly warm up to the top, almost the same as the downstairs ones, didn't emit any air noise but no signs of water either when I bled it which suggests the water level has dropped again. What could make that happen?

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Re: Central Heating Problems

#489761

Postby UncleEbenezer » March 28th, 2022, 2:43 pm

Bouleversee wrote:Many thanks again to you and other contributors on here. It is not easy to cope with such issues at my age and with IPF. Incidentally, neithrr of the chaps who came last week were wearing masks which is why I tried to keep away from them. It is quite a while since I had my booster and will not be having the latest booster till Wednesday. It would probably be fatal if I caught Covid with my lung disease. My sister caught it when she was in hospital for something else in January and died.

Your chance of it killing you is much less than you imagine.

At age 60, I'm the (joint) youngest of several of my friends who picked it up at - almost certainly - the same time and place. The oldest has turned 80 and had a stroke. None of us has suffered anything worse than a regular cold. I'm just annoyed that despite the symptoms being long gone I still test positive this morning, so will still need to absent myself from musical events today and tomorrow. :(

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Re: Central Heating Problems

#489780

Postby stewamax » March 28th, 2022, 4:03 pm

I hesitate to post a 'most likely' solution, but here goes:
- your feed and expansion tank hasn't been cleared of brown gunge for years (if ever)
- your plumber had to drain some water from the rads, necessary even when using a pipe freezer on the pipes at both ends
- when the pipes unfroze and a gush of water came from the header tank, it sucked some gunge with it
- this gunge blocked your micro-bore pipes

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Re: Central Heating Problems

#489785

Postby Bouleversee » March 28th, 2022, 4:19 pm

So the engineers came and I tried to discuss the various possibilities as suggested but could barely get a word in. They said that if the overheat stat had tripped and could be reset it must have been set too high. It had previously been set to 2 but last time he was here he had turned it up to 4 so he has now turned down again to 2. He put some water into the vent/valve at the opposite end from the bleed valve of each of the upstairs rads and says he added a little inhibitor. He said that he didn't have a test kit for the latter on his van. (I wasn't peering over their shoulders as they hadn't brought any masks; perhaps they don't know that the infection rate is rising). Water still wasn't coming out of the bleed valve so he asked if I had a paper clip to give it a bit of a poke which he said did the trick. They then departed in a puff of smoke, having been here no more than 10 mins. A few mins. later sitting in a chair close to the wall next to the garage, I heard a bang and went out to the garage, wondering if it was the lower part of the boiler casing coming adrift again; it was. Interestingly, it only comes off on one side and is held on by a strip of metal which hits the control knob knocking the temperature down to No. 1, as though it was designed to do just that. Is it? I have no idea how to fix it

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Re: Central Heating Problems

#489787

Postby Bouleversee » March 28th, 2022, 4:30 pm

stewamax wrote:I hesitate to post a 'most likely' solution, but here goes:
- your feed and expansion tank hasn't been cleared of brown gunge for years (if ever)
- your plumber had to drain some water from the rads, necessary even when using a pipe freezer on the pipes at both ends
- when the pipes unfroze and a gush of water came from the header tank, it sucked some gunge with it
- this gunge blocked your micro-bore pipes


Quite likely, but what can be done now? I don't recall anyone asking me where the expansion tank was when servicing a boiler till these engineers (?) asked me where it was after they had drained the rads and turned the system back on, only to find that 2 rads weren't heating at all. Why isn't the whole system checked when a service is carried out? What exactly does a boiler service consist of? From my experience the men doing it seem to be on their phones or having a fag most of the time. Why aren't they looking for gunge and testing the inhibitor level? Incidentally, do the various makes mix? Mine had Fernox in previously but he said he didn't use that and wouldn't have added anything if I hadn't suggested it yet again today.

I don't think they liked me trying to ask questions and make suggestions.

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Re: Central Heating Problems

#489950

Postby 88V8 » March 29th, 2022, 10:13 am

Bouleversee wrote:The top of the rads in my office is 28.5 inches from the floor; the bottom of the expansion tank in the eaves cupboard on the opposite side of the office is approx. 45.5 inches from the floor and it is approx. 13" high so should be ok according to you so he can't blame the system and insist on installing a sealed system, can he?

I wonder why they used my loopaper instead of the foam sleeves.

Because they're clods. Or they didn't have the right size sleeve for 8mm pipes.

That height difference is fine.

Bouleversee wrote:....what can be done now?

I don't think they liked me trying to ask questions and make suggestions.

Which is a bad sign in my experience.

Bouleversee wrote:....I heard a bang and went out to the garage, wondering if it was the lower part of the boiler casing coming adrift again; it was. Interestingly, it only comes off on one side and is held on by a strip of metal which hits the control knob knocking the temperature down to No. 1, as though it was designed to do just that. Is it? I have no idea how to fix it

Sounds as if there's a bit of an unburnt gas build-up, and then it's igniting.
Maybe there's a loose connection between the gas valve and the burners.
That would bother me.

So now there are two problems, the blockage and the boiler.

I've never had a boiler serviced, in the 35 years that we had central heating. It just... worked.
But I can imagine them looking at nothing but the boiler itself.

I think you should find another engineer to look at the boiler. If he seems intelligent and willing to listen, you could then tell him about the blockage etc.

What I might try if it were my system is to connect a hose to the drain cock of the system, if there is one, shut all the trvs and try to blow the blockage back into the tank.

Otherwise I would drain the system remove all the rads take off the trvs and then connect an air pump from rad to rad to find where it's blocked. But I wouldn't want to think what it might cost to have someone else do it.

I do feel for you. I hate having to depend on other people; I just spent two days sorting out a bodged repair on my Land Rover done by a garage that allegedly knew what they were doing.

As for your heating I would start now with an engineer to look at your boiler before it blows you up, unless Mike is able to come and help.

V8

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Re: Central Heating Problems

#489977

Postby Mike4 » March 29th, 2022, 11:05 am

88V8 wrote:As for your heating I would start now with an engineer to look at your boiler before it blows you up, unless Mike is able to come and help.

V8


I know you said this semi-jokingly, but people do take these things seriously and worry.

There is virtually no chance of of the boiler blowing the OP up. The Prima very occasionally suffers from explosive ignition which can in extremis, blow the front panel of the boiler off, but that's about it. I've seen it once in my career to give some perspective. I wasn't there at the time, just called in later to fix it.

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Re: Central Heating Problems

#490023

Postby 88V8 » March 29th, 2022, 12:42 pm

Mike4 wrote:The Prima very occasionally suffers from explosive ignition which can in extremis, blow the front panel of the boiler off...

Ah, thankyou.
Well if you're happy that it's not dangerous, I'm sure the OP can relax.

Although it still leaves her original problem.

Incidentally, I read somewhere that it's an offence to remove the casing of a gas appliance if one is not 'competent' in that one does not have the paperwork to prove competence.
I'm sure the boiler does not have said paperwork, so is it committing an offence when it blows its own front off?

V8


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