Boiler Losing Pressure Issue

[DerekR78]

Hi,

Looking to see if anyone can give some advice please.

My Baxi boiler has been losing pressure and I am having to top it up approx. every 4 hours from 0-1.5 bar each time. This has been going on a week now.

I have also started to notice small drips running down my condensate pipe, internally before it passes through the wall to outside. This has only started today. I have went round all may radiators and does not seem to be any leak from valves/connections or any sign of water running down pipework to floor. There also does not seem to be any visible signs of water on ceilings. Can't check ground floor pipework as we have tiled and wooden flooring.

I have currently turned off flow & return heating valves under boiler and switched boiler to hot water from taps only? If I still lose pressure would this narrow it down to something inside the boiler and not on the actual heating pipework / radiators??

I have had a new heat exchanger fitted few years ago and starting to wonder if this has went again, but how would I know this?

Looking to see if anyone can point me in any direction for things to try and hopefully narrow it down a bit. Just hoping its not some sort of issue in pipework. Last thing I want to do is going ripping up floors so that's last resort.

Thanks
Derek

 

[Ben-gee]

Yes you are doing a good test.
With boiler isolated from central heating pipework, if the pressure still drops it is an issue with the boiler - probably the heat exchanger.
If pressure holds for a day. Then reconnect the CH pipework ( by opening the isolation valves) if the pressure now drops immediately - the issue is with the CH ie pipes or radiators.

 

[DerekR78]

Yes you are doing a good test.
With boiler isolated from central heating pipework, if the pressure still drops it is an issue with the boiler - probably the heat exchanger.
If pressure holds for a day. Then reconnect the CH pipework ( by opening the isolation valves) if the pressure now drops immediately - the issue is with the CH ie pipes or radiators.

So by shutting off the flow and return valves under the boiler will this definitely rule out any pipework/radiator issue? I also switched off central heating setting on boiler, so boiler was only supplying hot water to taps.

The pressure still seems to be dropping.

I have found a small crack at joint in plastic condensate pipe, but as this only started this morning, I presume this has nothing to do with pressure anyway so possibly it was myself caused this this morning when I was feeling about it for any water and dislodged it.

 

[KenDailman]

Hi Derek,

It seems like you're facing a challenging situation with your boiler. The pressure loss issue and the drips from the condensate pipe are causes for concern.

Shutting off the flow and return heating valves to check if the pressure loss persists is a good move. If the pressure still drops when the boiler is set to hot water only, the problem might lie within the boiler itself rather than the heating pipework or radiators. The past replacement of the heat exchanger could be a factor.

For an accurate diagnosis, it's advisable to consult a heating engineer or plumber who can perform a thorough inspection and necessary tests. While I understand your reluctance to tear up floors, seeking professional assistance is often the best course of action. By the way, since you're interested in a heat pump, you might consider heat pump water heaters as an energy-efficient solution for your hot water needs.

 

[cjg]

put a balloon over your prv pipe out side see if it gets water in. to see if yours is passing

 

[DerekR78]

put a balloon over your prv pipe out side see if it gets water in. to see if yours is passing

Definitely no water coming out external copper pipe which I presume is the prv

 

[DAVE the old git]

Hi Derek,

It seems like you're facing a challenging situation with your boiler. The pressure loss issue and the drips from the condensate pipe are causes for concern.

Shutting off the flow and return heating valves to check if the pressure loss persists is a good move. If the pressure still drops when the boiler is set to hot water only, the problem might lie within the boiler itself rather than the heating pipework or radiators. The past replacement of the heat exchanger could be a factor.

For an accurate diagnosis, it's advisable to consult a heating engineer or plumber who can perform a thorough inspection and necessary tests. While I understand your reluctance to tear up floors, seeking professional assistance is often the best course of action. By the way, since you're interested in a heat pump, you might consider heat pump water heaters as an energy-efficient solution for your hot water needs.

It could be that the PRV is passing or even the Expansion Vessel is gone When the heat exchanger was replaced the PRV was propyl used to drain down the heat exchanger then what tends to happen then dirt get under the seating of the valve then when the heating is on full the PRV starts to leek this is how you can loose pressure at a quick rate

 

[cjg]

the op says no water in prv balloon so not prv or ex vessel