Finding a leak on a combi

[Harry Bloomfield]

how do I check the valve?

Exactly as you would for the valve on a car tyre - Remove the valve cap, lick the end of your finger and wipe it over the end of the valve to check for any bubbles. A more certain way to check, to check the actual valve and around the valve, is to spray around the entire valve area with a water / washing up liquid mix. Again, you are looking for any sign of bubbles.

 

[trevorbayliss]

Ok thanks. I have some gas detection spray so will try that.

 

[DP]

This all stems from me leaving a cleaner in my system last spring.

Cleaner has done its job The magnetite acts as a sealing agent aside causing others issues. You have a clean system including the weakness that is now devoid of the sealing properties of magnetite leading to system pressure loss.

I assume you thoroughly flushed out the cleanser (6/7 fill and drains is not unusual)

 

[trevorbayliss]

DP

no I didn’t flush many times. Just once I think and I didn’t flush the ufh loop as I didn’t know how to drain it.

so really I need to flush my system again a few times. But I do think this is the cause of my issues.

getting all these replies brings me back to Trying the leak sealer when I fit the new magnaclean 2.

thanks all for helping, every comment helps out.

 

[CBW]

I mentioned in post #13, try taking the pressure to approx 2.8 bar. Did you do this?

In doing this you can sometimes expose a leak, that isn’t always visible.

 

[picasso]

I mentioned in post #13, try taking the pressure to approx 2.8 bar. Did you do this?

In doing this you can sometimes expose a leak, that isn’t always visible.

To be honest I think this is poor advice, your more likely to cause leaks than find them, don't forget the ops system is more than 30 years old.

 

[John D v2.0]

. Initially the pressure held for longer, but it looses pressure very quickly once you get down to 0.8 bar.

That's because that's the charge pressure of your expansion vessel so there is no more water in it to maintain the pressure in the rest of the system.

 

[dilalio]

@trevorbayliss do you have any pipework that runs under a suspended ground floor?

If so, it can leak there and you'll never see it unless you pull up a few floor boards.

 

[trevorbayliss]

I do in my extension (2 rads) but I can isolate this off and have done so.

the rest of the house is solid floor so pipes are visible in many places.

a lot of the pipe work I can expose due to wood floors and I can’t see any signs of leaks here.

 

[trevorbayliss]

Update:

I think i have found my leak. Just done a drain down in order to clean out my secondary heat exchanger and change over to a new filter.

Well my drain off valve is still leaking after doing a fill up. This is quite noticeable. So i need a new washer. However, i think this is where i had my leak, but it never showed up on the floor area as it just evaporated away.

So fingers crossed this has been my issue. Will find out in a few weeks time if so.