Loss of heat circulation in boiler

[moorfield]

Ho hum my replies on t'other thread have jinxed the combi at Moorfield Towers, in the first really cold snap of the month ...

Arrived home tonight to a cold house and un-operating boiler the thermostats all calling for heat. Turned on the hot water to see the boiler temperature overheat very quickly to 100 degrees with a lot of clicking noises. We've lost heat circulation, a pump and/or electronics problem, I think.

What's really ferking frustrating is this is a new Worcester installed last August, CH & DHW running fine through the autumn. However I am not going to fault the excellent plumbing company that installed it, would recommend to anyone. I'll be on the phone to them tomorrow.

Cheap Chinese parts, I wonder. Are these things deliberately designed to fail ? Should be a warranty job, I sincerely hope.

[Gerry557]

It could be a pump or sticking valve.

It's that time of year I'm afraid. Probably worth doing a test run in autumn so you have time to find any issues after being dormant all summer. I bet there are lots of call outs in a cold spell.

[BullDog]

It could be a pump or sticking valve.

It's that time of year I'm afraid. Probably worth doing a test run in autumn so you have time to find any issues after being dormant all summer. I bet there are lots of call outs in a cold spell.

Presumably, being a combi boiler, it has been supplyin̈g hot water all summer when the heating has been off. So it won't have been shutdown for any period of time. Personally I wouldn't buy a Worcester Bosch boiler, but that ship has sailed. Hope it's sorted under warranty very soon.

[Mike4]

Ring Worcester directly as it will still be under warranty. They have excellent after-sales service in situations like this.

[moorfield]

Ring Worcester directly as it will still be under warranty. They have excellent after-sales service in situations like this.

Yes. And the answer to this conundrum is they replaced the plate heat exchanger, which seemed to have a little bit of debris/scale in it, but the boiler passed the engineers so called "clean water checks" (whatever they are). I am really surprised/frustrated/perplexed this has happened after 8 weeks or so of (light) usage the system has all the recommended filters and strainers on it. What worries me know is if this happens again they might try to nix any further warranty repair.

[scotview]

in the first really cold snap of the month ...

Have you had any significant frost? Could be your condensate drain pipe frozen.

[88V8]

Ring Worcester directly as it will still be under warranty. They have excellent after-sales service in situations like this.

Yes. And the answer to this conundrum is they replaced the plate heat exchanger, which seemed to have a little bit of debris/scale in it, but the boiler passed the engineers so called "clean water checks" (whatever they are). I am really surprised/frustrated/perplexed this has happened after 8 weeks or so of (light) usage the system has all the recommended filters and strainers on it. What worries me know is if this happens again they might try to nix any further warranty repair.

Modern boilers with their alloy heat exchangers are too fragile, which is not a very helpful comment when all one can buy is modern boilers.

Is your water hard?
And when your new boiler was installed, did the engineer test-fire it with no water treatment in the system? That would be enough to put a flash of scale on the exchanger, a flash which an iron heat exchanger would shrug off, but which can be detrimental to an alloy unit.

V8

[BullDog]

Yes. And the answer to this conundrum is they replaced the plate heat exchanger, which seemed to have a little bit of debris/scale in it, but the boiler passed the engineers so called "clean water checks" (whatever they are). I am really surprised/frustrated/perplexed this has happened after 8 weeks or so of (light) usage the system has all the recommended filters and strainers on it. What worries me know is if this happens again they might try to nix any further warranty repair.

Modern boilers with their alloy heat exchangers are too fragile, which is not a very helpful comment when all one can buy is modern boilers.

Is your water hard?
And when your new boiler was installed, did the engineer test-fire it with no water treatment in the system? That would be enough to put a flash of scale on the exchanger, a flash which an iron heat exchanger would shrug off, but which can be detrimental to an alloy unit.

V8

That's where a bit of research can be helpful. It's possible to buy boilers that have stainless steel heat exchangers, some of them with a ten year warranty.