High water Pressure after leaking gas pipe

[Marvt74]

Hi

We recently had a gas leak in our house (my fault, trying to secure floorboards and a nail clipped a pipe!). A plumber came out and fixed the pipe. However ever since he’s been the boiler has a pressure of around 2.5 whereas it's normally around 1 when there is no heating on. It's also making the kind of noise if makes when the heating is on.

Normally when I’ve had low pressure I’ve used a tap to “top up” the boiler to around the 1.5 mark and monitored it. However opening that tap now it quickly drops the pressure to where I want it, however when I close it again the pressure quickly jumps up to around 2-2.5.

Can anyone explain what may have caused this to have suddenly jumped up? When the plumber had finished fixing the leaking pipe he adjusted something on the gas meter and said something about correcting the pressure but I’m not really sure what this could have been.

The boiler is a Worcester 28i

 

[glenno1]

Try bleeding radiators a bit to bring the pressure down

 

[wheeto]

Are you saying that the pressure increases when the filling loop valve is open? Disconnect the filling loop / remove the filling "key" and see what happens.

 

[mountainman]

You could ask your plumber if he did anything that may have caused your current concern.

 

[Bernie2]

Usually unrelated. There is a possibility of course that in an extreme case he has increased the gas pressure to the boiler. I think its highly unlikely though. What I was thinking is that if the boiler had been under gassed and only working on a low modulation, a rise in gas pressure would allow it to increase its burner rate. A bit like a gas tap on a cooker, if it is turned low things boil slower, if turned up they boil faster. This would then make for a temperature rise and possibly an increase in system pressure.

I would advise getting the boiler serviced, that should show up any problems.

 

[AWheating]

sounds like your filling loop set up may be passing? or even your expansion vessel may need a re charge? it should not have had anything to do with the gas pipework. If the boiler has not been serviced in the last 12 months then arrange a service and ask the engineer to do a few checks.

 

[SimonG]

Is the pressure relief pipework (normally piped outside) letting water out?

It sounds like the filling loop is passing or the plate heat exchanger has gone, that is split internally and is passing mcw into the heating water. You could test this by turning mcw off to boiler.

Best bet is get an engineer to have a look at it.

 

[Bernie2]

If you know the mains cold water pressure and its about the same as the boiler pressure it may indicate a leaking plate heat exchanger as SimonG says.

 

[breakdown]

If it's a 28i rsf i dont think they have a plate heat ex ?