Combi boiler pressure rises slowly over time

[mg1969]

Hi all.

I have a Glowworm Flexicom 80 boiler. It is about 1.5 years old, and a few months ago we had a flood in the house, so things got disconnected etc.

Since then, the boiler pressure has been going up and up. Standard pressure is 1 bar, but it has risen to nearly 2 bar (this is all when cold, ie, no heating is being used) over some weeks.

I have drained the whole system and refilled thinking I might have trapped air in the system, but this has not helped. All radiators are air free.

I have also bled some water off from the system to get the pressure down and sure enough, pressure slowly rises again.

I have read faq's. Is this something to do with the pressure/expansion vessel? Should I drain it? Or could it be that the Heat Exchanger in the boiler has perforated?

Appreciate any advice.

 

[kevplumb]

filling loop passing

 

[mg1969]

Hi Kev.

Thanks for the reply.

The filling loop is attached, but both taps are off. Are you saying the valves are leaking?

What is the solution in this case? Changing valves?

 

[namsag]

Disconnect the loop and check

 

[kevplumb]

disconnect the silver braided pipe first and see if there is any leakage

apart from the little you will get at first

 

[picasso]

disconnect the filling loop, if the pressure still rises the plate heat exchanger has a pinhole passing into the ch system

 

[mg1969]

Cheers guys.

I'll see if I can get the loop disconnected then and check for leaks.

One thing I didn't mention, is that the contractor who worked on our house after our flood and who got the system going again broke one of the plastic taps of the filling valves. When I tried turning it, it just spun in air. He must have forced it round the wrong way and in so doing wore away the inside of the tap. Maybe this damaged the valve?

To open and close it, I had to use a screwdriver.

 

[dextrous]

I think you have identified the problem.

 

[bengasman]

As mentioned above, disconnect the filling loop; it will answer both questions.