Hi please help!! Since having my central heating put in 12 months since I have had a constant whooshing thought the pipes. It sounds like a kettle boiling. The plumber has been back and put some stuff in the pipes to quieten it down and then came back again and took the thermostat off the the radiator and capped it. This has stopped the noise starting for about 2 hours instead of the usual 1/2 hour but it is still hard to live with. Anybody any ideas, it is driving me around the bend.
Baxi Combi 105e whooshing through pipes
- Thread starter janetk
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It sounds as if its the TRvs closing and that he has not fitted an auto bypass!
When it starts making the noise try opening a TRV to maximum and see if that stops the noise.
If so then get him to fit an auto bypass valve! He should have done that in the beginning.
They cost about £17 and its amazing what some people will do to save that small cost.
Tony
When it starts making the noise try opening a TRV to maximum and see if that stops the noise.
If so then get him to fit an auto bypass valve! He should have done that in the beginning.
They cost about £17 and its amazing what some people will do to save that small cost.
Tony
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Hi Thanks for that. I know this is a silly question but is TRV the knob with the numbers on on the radiator? If so, I have tried with them all on full and it is fine, so someone suggested to me that one of them could be faulty, does this sound feasible.
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Agile said:
You dont know what your on about mate it has an integral bypass built in and can be fitted to a fully trv system
i would get him to check if all the trvs are on the right way round thats assuming he hasnt fitted reversible flow models
Just because a boiler has an integral bypass built in doesn't mean you don't need to fit an additional one.
Remember the integral bypass is often fitted by the manufacturer to protect the boiler from a no flow situation (not necessarily to produce a quiet system)
Most combi's including the 105e have a 6 meter pump (set on highest speed for the DHW). If the system only comprises of a few radiators and they have TRV's fitted the internal bypass may be insufficient.
Check out the maximum differential pressure permitted accross TRV's, with small systems and high head pumps this can be exceeded resulting in noise.
Also worth checking lockshields - sometimes a small adjustment can make a substantial difference to noise.
Remember the integral bypass is often fitted by the manufacturer to protect the boiler from a no flow situation (not necessarily to produce a quiet system)
Most combi's including the 105e have a 6 meter pump (set on highest speed for the DHW). If the system only comprises of a few radiators and they have TRV's fitted the internal bypass may be insufficient.
Check out the maximum differential pressure permitted accross TRV's, with small systems and high head pumps this can be exceeded resulting in noise.
Also worth checking lockshields - sometimes a small adjustment can make a substantial difference to noise.
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You cant turn around to an installer and say you should have fitted a bypass in the system when in the installation instructions it clearly states
6.3 Bypass
1. The boiler is fitted with an automatic integral bypass.
what differance does it make if the boiler only has a couple of radiators you can shut the flow and return isolation valves of underneath the boiler if you wanted and it would run quite ok without any noises the issue is with the trvs that have been fitted they are obviously on the wrong way round or cheap ones
6.3 Bypass
1. The boiler is fitted with an automatic integral bypass.
what differance does it make if the boiler only has a couple of radiators you can shut the flow and return isolation valves of underneath the boiler if you wanted and it would run quite ok without any noises the issue is with the trvs that have been fitted they are obviously on the wrong way round or cheap ones
So what if the manual states the boiler has an integral bypass, its a fixed rate and its main purpose is to protect the boiler.
Some boiler manufactures eg Vaillant offer different spring rates to suit the system.
Some manufacturers technical teams will advise additional bypasses be fitted especially when most rads have TRV's.
OK turn down the isolating valves but thats bad practice and not what their designed for.
My point is high differential pressure across the TRV's may cause the noise especially when several valves start to close down - and a fully adjustable bypass valve correctly setup may solve the problem.
I agree some TRV's may be more noisy due to there design.
Some boiler manufactures eg Vaillant offer different spring rates to suit the system.
Some manufacturers technical teams will advise additional bypasses be fitted especially when most rads have TRV's.
OK turn down the isolating valves but thats bad practice and not what their designed for.
My point is high differential pressure across the TRV's may cause the noise especially when several valves start to close down - and a fully adjustable bypass valve correctly setup may solve the problem.
I agree some TRV's may be more noisy due to there design.
Gaz said :- """You dont know what your on about mate it has an integral bypass built in and can be fitted to a fully trv system"""
Well, the customer has now confirmed that with all TRVs on full then the system is quiet.
Either there is a faulty TRV or they are non reversable and have been reversed or most likely they are just a little noisey and in that case the cure will be an auto by pass. Unless the boiler's built in one has become stuck of ccourse.
Its well known that built in bypasses are incorporated primarily to protect the boiler and will sometimes need an external bypass fitted to ensure quiet operation.
Tony
Well, the customer has now confirmed that with all TRVs on full then the system is quiet.
Either there is a faulty TRV or they are non reversable and have been reversed or most likely they are just a little noisey and in that case the cure will be an auto by pass. Unless the boiler's built in one has become stuck of ccourse.
Its well known that built in bypasses are incorporated primarily to protect the boiler and will sometimes need an external bypass fitted to ensure quiet operation.
Tony
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Agile said:
which tells me that its the trvs
all im saying is that you were giving advice stating that an external bypass should have been fitted when this isnt the case as the manafacturers installation instructions state that one is not required
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your repeating wot i put earlier
it also doesnt say that it needs one either
trust me if it needed an external bypass then it would say so as it does in all the other installation instructions where it needs one
it also doesnt say that it needs one either
trust me if it needed an external bypass then it would say so as it does in all the other installation instructions where it needs one
Gasguru said:
Surely if it required an additional by-pass the manf inst would state so.
Im with Gaz on this one. A large proportion of Combis now on the market dont require a by pass fitting.
If the manufacturer hasn't fitted one they may well state you need to fit an external bypass.
The last thing they need are warranty callouts due to overheating boilers when the TRV's shutdown, wheelheads are closed off, zone valves shut.
We've all been to plenty of houses where the occupants turn off the rads using the valves and not the boiler controls.
The manufacturers don't give a toss if your systems noisy due to flow rates being too high - so they aren't necessarily going to tell you install an additional bypass on a low head system.
Remember the integral bypass is set at a specific rate - its spring rate must be high enough to allow a system to operate on the highest heat load output of the boiler.
With many combi installations the real heat load may be only a fraction of the boilers maximum output and the integral bypass may not open sufficiently.
The last thing they need are warranty callouts due to overheating boilers when the TRV's shutdown, wheelheads are closed off, zone valves shut.
We've all been to plenty of houses where the occupants turn off the rads using the valves and not the boiler controls.
The manufacturers don't give a toss if your systems noisy due to flow rates being too high - so they aren't necessarily going to tell you install an additional bypass on a low head system.
Remember the integral bypass is set at a specific rate - its spring rate must be high enough to allow a system to operate on the highest heat load output of the boiler.
With many combi installations the real heat load may be only a fraction of the boilers maximum output and the integral bypass may not open sufficiently.
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