stabilizing the inlet supply pressure on a promax combi

[jcochr]

I have a Potterton Promax combi 28 HE A and it runs a pump when cold taps are turned off and there is a slight change in inlet pressure. I am thinking of putting a pressure reducer or non-return valve and/or an arrestor on the inlet pipe. I tried putting an arrestor on all the cold taps and reducing the pressure but this did not completely stop the problem. The cold taps must be closed off very slowly to prevent the boiler starting. Has anyone seen this problem before? Thanks.

 

[EvilDrPorkChop]

I have a Potterton Promax combi 28 HE A and it runs a pump when cold taps are turned off and there is a slight change in inlet pressure. I am thinking of putting a pressure reducer or non-return valve and/or an arrestor on the inlet pipe. I tried putting an arrestor on all the cold taps and reducing the pressure but this did not completely stop the problem. The cold taps must be closed off very slowly to prevent the boiler starting. Has anyone seen this problem before? Thanks.

Non return valve on cold inlet with a Shock Arrestor/Mini Golf ball expansion vessel after the non return valve.

 

[jcochr]

Non return valve on cold inlet with a Shock Arrestor/Mini Golf ball expansion vessel after the non return valve.

Yes - that's the idea. I have bought a Peglar 62 and have got both a single and double check valve. I suppose compression is better than push fit... I don't know if it is better for single or double and compression or push fit.

 

[EvilDrPorkChop]

I'd probably go Compression double check valve. The Peglar 62 will be good, I fit a similar design from a different brand and they work well.

 

[jcochr]

I'd probably go Compression double check valve. The Peglar 62 will be good, I fit a similar design from a different brand and they work well.

Thanks... I will put an isolation valve, then check valve then Pegler 62... Hopefully, no more annoying pump running when I switch off the cold tap!

 

[jcochr]

Thanks... I will put an isolation valve, then check valve then Pegler 62... Hopefully, no more annoying pump running when I switch off the cold tap!

It worked - no more boiler cycling when I close the cold tap.

 

[jcochr]

Non return valve on cold inlet with a Shock Arrestor/Mini Golf ball expansion vessel after the non return valve.

It worked... maybe the boiler has a non return valve internally that is not so strong