Boiler startup noise

[Jever]

Hi all,

A couple of years ago, I had my water system changed to a direct feed system, so that I no longer have any tanks in the loft and the heating system is now a closed system.

It works quite well, the pressure's good, but there's one really annoying problem. Every time the boiler fires up (e.g. for water and heating at 6 in the morning), it makes a really loud noise that penetrates through the whole of the house. It also tends to do it if someone's in the shower and the boiler needs to come on to reheat the water in the tank.

I filmed it and loaded it onto Youtube for the world to enjoy:

Does anyone have any idea what might be causing it? Sometime's it's so loud I worry something's going to rupture and flood the house.

Also, over time, the system loses pressure. I usually keep it at one bar, but I think the problem with the noise may be linked to it. For example, the boiler just started up and it made the noise and the pressure guage dropped from 1 bar to 0.9 bar. I'm not aware of any leaks in the system, so where on earth could the water be going? Usually, after about a week, I'll have to open the taps up and bring it back up to one bar.

I'd really love to solve this problem, as I could then sleep past 6am and I could stop worrying about there being a leak somewhere in the system.

Regards

Jever

 

[Dan Robinson]

Could be the zone valve plumbed backwards.

 

[ianmcd]

as @Dan Robinson says it sounds like you have a zone valve fitted the wrong way round, the brass body will have a direction arrow on it check that out, your pressure problems are not related, your pressure guage dropping by 0.1 of a bar on startup is normal it is just the pump kicking in

 

[Jever]

Hi,

That seems a rather basic error, considering how much I paid the plumber to do it.

Would I be right in thinking that the arrow on the brass casing in the attached photo should be pointing upwards, so that the water flows into the coil?

Thanks for your help, both of you, by the way.

Jever

 

[CWHEATING]

I’ve came across zone valves being plumbed in backwards before but always just left them. I had no idea it could cause that kind of noise.

 

[Dan Robinson]

Hi,

That seems a rather basic error, considering how much I paid the plumber to do it.

Would I be right in thinking that the arrow on the brass casing in the attached photo should be pointing upwards, so that the water flows into the coil?

Thanks for your help, both of you, by the way.

Jever

They point in the direction of flow. This can be either way depending on the installation.

 

[CWHEATING]

Coil 1. M guessing that means flo

They point in the direction of flow. This can be either way depending on the installation.

I guess so but be honest it’s more than likely the problem at hand. So

 

[OvertonPlumber]

The motorised valve. Is a polypipe honeywell clone they later became branded ESI. They have a faulty switch relay which causes the chattering. Good thing is the head is easily changed the new ones dont have the plug in lead so you would have to put a joint box in wago grey box etc.
I probably changed 50 of them. Got so bad people were binning them and fitting real Honeywells instead.

Plus yours is backwards. By the looks of it.

Port a----port b or follow the arrow

I would also be asking where the automatic bypass valve is ???
https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/231774588623

 

[CWHEATING]

The motorised valve. Is a polypipe honeywell clone they later became branded ESI. They have a faulty switch relay which causes the chattering. Good thing is the head is easily changed the new ones dont have the plug in lead so you would have to put a joint box in wago grey box etc.
I probably changed 50 of them. Got so bad people were binning them and fitting real Honeywells instead.

Plus yours is backwards. By the looks of it.

Port a----port b or follow the arrow

I would also be asking where the automatic bypass valve is ???
https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/231774588623

Let’s not forget while a bypass valve is good practice to fit, it only needs one if there is a pump over run. Some boilers

The motorised valve. Is a polypipe honeywell clone they later became branded ESI. They have a faulty switch relay which causes the chattering. Good thing is the head is easily changed the new ones dont have the plug in lead so you would have to put a joint box in wago grey box etc.
I probably changed 50 of them. Got so bad people were binning them and fitting real Honeywells instead.

Plus yours is backwards. By the looks of it.

Port a----port b or follow the arrow

I would also be asking where the automatic bypass valve is ???
https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/231774588623

While it’s good practice to fit bypass valves, let’s not forget if there is no pump overrun then it doesn’t necessarily need one. Some boilers like for example the new ideals don’t require a permanent live, so no pump overrun, no bypass required. Obviously most boilers require one and I’d always fit one ti the system as it good practice like I stated above, but let’s not worry the guy to much.

 

[dilalio]

@Jever : That noise made you jump, whilst filming didn’t it!

 

[Jever]

Hi Mr Benchmark,

That's really helpful information, thanks.

I took a picture of the side of the motor box just to check and you're right, it's an ESI product (see file attached).

If I'm honest, I'm not certain if the valve's the right way round or not, but looking at the plumbing, there's another pipe at the same height going into the tank, also marked 'COIL 1'. Just before that comes the Honeywell three-way valve that splits the flow between water and central heating feed and then just before the three way valve is the pump.

This suggests to me that the valve making the noise is at the outlet and hence the valve is fitted the right way round. That said, I'm no expert.

I think if I could have satisfied myself that the only problem was that it was installed the wrong way round, I'd have had a go at turning it round myself. However, it appears the core of the problem is a faulty product and I think I'm out of my depth now, so I think it's time I got a qualified plumber took look at it. Is putting it right a big deal or can it be done without opening the pipes/some sort of drain down?

Once again, thanks for your help.

Jever

 

[dilalio]

Work on a uv needs to be done by someone with the appropriate qualifications: g3 registered.

 

[Gasguru]

Let’s not forget while a bypass valve is good practice to fit, it only needs one if there is a pump over run. Some boilers

While it’s good practice to fit bypass valves, let’s not forget if there is no pump overrun then it doesn’t necessarily need one. Some boilers like for example the new ideals don’t require a permanent live, so no pump overrun, no bypass required. Obviously most boilers require one and I’d always fit one ti the system as it good practice like I stated above, but let’s not worry the guy to much.

I think you forget....an auto bypass is often required to comply with the minimum flowrate through the boiler under all system flow conditions, to reduce the differential pressure across TRVs as well as providing a flow path under pump overrun conditions. Of course the next problem is the often incorrect setting of the valve.

 

[CWHEATING]

I think you forget....an auto bypass is often required to comply with the minimum flowrate through the boiler under all system flow conditions, to reduce the differential pressure across TRVs as well as providing a flow path under pump overrun conditions. Of course the next problem is the often incorrect setting of the valve.

I think you forget....an auto bypass is often required to comply with the minimum flowrate through the boiler under all system flow conditions, to reduce the differential pressure across TRVs as well as providing a flow path under pump overrun conditions. Of course the next problem is the often incorrect setting of the valve.

is that why it’s good practice to have one bypass radiator fitted with lock shields on a combi fed system. I’d imagine so.
Yeah setting up a bypass valve seems to one thing that’s never done correctly. The amount of times I’ve gone to call outs where rads have not been getting hot because of short circulation caused by bypass valves being opened to much.

 

[Jever]

Just as an add-on to my earlier comments, I've referred back to the invoice for the job and it specifically lists a 22mm auto by pass valve as part of the job. Is it possible that the plumber's fitted it, but it's not evident from the video?