Ideal combi 30 boiler - odd noise. Please listen and help if you can

[PhilippeMontrose]

Hello guys. I have an Ideal Combi 30 boiler. It makes an odd noise and I would love someone to say what it is.

This ONLY happens on heating, never on hot water. WIthin a few seconds of heating been called, the boiler makes a deep, booming vibration a bit like a low didgeridoo being played. If you place you hand on the case, you can feel the noise (Slade record, yes I know!).

I am more curious than anything. Boiler serviced this year after we moved in. Had new gas valve, new sump, new burner at the top and was totally stripped down bar the pump by the chap that serviced it - yes he is gas-safe registered. He also serviced the bypass valve, fitting new pistons, seals, o rings etc. I watched him do it as I am nosey and curious, plus we had a cuppa each and a talk about football.

I would best describe this noise as a low vibration or boom sound. A bit like dragging a very heavy wardrobe across a solid wood floor in the flat above you. It literally lasts a seond or two at most.

As this ONLY happens on heating, (I am purely guessing now) I would have thought it might be the bypass valve as it has to move for heating, or the central heating pump. But it only does it for a seond or so. It might do it 3 or 4 times over an hour when the heating is on.

Any ideas?

Much appreciate any thoughts.

Youtube video not great, but the only time I managed to catch it.

Thanks in advance.

 

[cross thread]

might be the diverter valve moving into heating position ,can’t see it being the pump as that’s used on h/w and heating

 

[gas112]

How much did you pay for all those bits and labour ?

 

[kidgreen61]

Well known issue with Logics, and a simple fix for a gas bod who's familiar with them, as yours clearly isn't.

 

[PhilippeMontrose]

Thanks Cross Thread - exactly what I thought as it only happens when heating is called. A bit annoying as I saw the guy service the divertor valve as mentioned, otherwise I would not have believed it was done. He fitted a brand new 'service kit' which he even showed me. It had the two end nuts, valves, springs, new o-rings etc etc. He even told me he was using 'silicon grease' when I asked what the vaseline was for. So I know it was done, but it could still be that of course.

*Just re-read. I missed the end of your reply somehow. I di not know that the pump malso works on hot water. Leaqrned something there! I thought that was just for the heating, so thanks for putting my at ease and yes, that does make sense about the diverter.

 

[PhilippeMontrose]

Thanks Gas112 for replying. A lot! It was a close call between that and a brand new boiler. To be honest, he did say it didn't really need a new burner but that the original one was looking tired and as he had the old unit off and a brand new seled box in the van, it was not much on its own - £95 for that part if I remember, the sump - which was actually a long black tube thing is apparanttly a known fault - they crack. He showed me the crack so I jknow he was not making it up. The divertor valve was part of the standard service, I think the whole bill was just under £450 but the boiler works perfectly and is safe, other than the noise.

*My error, just looked at the receipt. Total was £439.97

 

[PhilippeMontrose]

@kidgreen61. Wow. That was a bit harsh!

I was chatting with the guy and we were drinking tea as he worked. I have never seen a more professional and decent plumber. He explained what he would be doing, started draining the system down, was concerned not to make a mess or get the laminate floor wet, talked me through what he was doing. He had the whole boier stripped to a bare shell in about 5 minutes. I was astonished. He clearly knew exactly what he was doing.

He showed me poarts as they came off, I could see how dirty and clogged looking the burner unit was. He took the main big metal unit outside and poured jugs of water in and showed me all the silvery gravel that came out. He defintely knew what to do.

If you think you know better, let me know what you think and I will happily pass that on the plumber who is coming back tomorrow.

 

[kidgreen61]

@kidgreen61. Wow. That was a bit harsh!

I was chatting with the guy and we were drinking tea as he worked. I have never seen a more professional and decent plumber. He explained what he would be doing, started draining the system down, was concerned not to make a mess or get the laminate floor wet, talked me through what he was doing. He had the whole boier stripped to a bare shell in about 5 minutes. I was astonished. He clearly knew exactly what he was doing.

He showed me poarts as they came off, I could see how dirty and clogged looking the burner unit was. He took the main big metal unit outside and poured jugs of water in and showed me all the silvery gravel that came out. He defintely knew what to do.

If you think you know better, let me know what you think and I will happily pass that on the plumber who is coming back tomorrow.

Who on earth drains a boiler & removes the entire heat exchanger just to wash it out?
Easily done in situ.
The noise you are hearing is related to the gas valve/venturi/injector.
Apologies for the unintended harsh tone, I just hate hearing of people being robbed.

 

[PhilippeMontrose]

Thanks for the response. No apology needed.

I asked him that just now. He said that otherwise you fill the ''syphon trap bottle'' with all the debris, which then takes quite a while to flush out. Which makes some sense to me, but I also get why you could do it in situ. But he also said it is only 2 screws and one nut to remove it, so it is easy to do and gives you a good look inside which you cannot do really well in situ. He also said it gives you a better chance to check the inside of the case for any corrosion and to pick up all the nuts and screws that previous plumbers inevitably drop inside the case.

I suppose different plumbers have their own favourite ways of doing things.

Bottom line is that he did a great job on the day.

Thanks for your help all. I will pass comments on and let you know what he finds.

 

[PhilippeMontrose]

Just as an update. Those who thought it was the diverter valve or venturi, WRONG!

It was simply the opentherm ESI ESRTP4RF+ that was the problem.

Apparently these controllers are nothing but problems. He fitted a wireless room thermostat instead of an opentherm one, and it has worked perfectly since.

Absolutely nothing the plumber did wrong. It was the opentherm room stat, not the boiler that was the prblem.

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