New CH System losing pressure

No - the pressure loss is in the sealed part of the system. You maybe have a pinhole leak or seep somewhere, or there's a small loss from overheat/overpressure releases.

No the drop is on the primary (radiator) side, not your domestic hot water supply. Have a look at the wiki article

In message , Kevin Cowans writes

The CH system is sealed and separate from the hot water system

Your pressure relief valve might not be seated correctly, but it sounds more like you have a leak - you (or your fitter) have to find it, the sooner the better as you are constantly introducing scale into, and diluting the inhibitor in (I presume you have some in) your system

If you watch and learn from the fitter (not engineer) when he comes to re-pressurise the system, you'll be able to do it yourself next time, won't you

?? WTF

Yeah, on reflection that was slightly redundant - the pressure relief valve isn't directly activated by heat, although excess heat might cause the excess pressure.

How do you know the OPs fitter doesn't have an engineering degree? (I assume you object to non graduates styling themselves as "Enginerer")

Mine did this for a year, gradually getting less and less as the thing stablised.

Now I re-presurise once a year and thats that.

There is always SOME water reacting with bits of old flux and metal to produce gas.

Keep bleeding and repressurising it yourself every so often,after informing said plumber taht this is what you are up to.

As it MAY be an actual teeny leak. Even those self heal over time though with hardish water.

Hello all

Thanks for all the replies.

I will continue to repressurise the system myself as needed and see how it goes.

Bye for now

Kev>> Hello all

I'm puzzled by this, and all the replies.

Surely as the guy has fitted this new system he's responsible for doing it right - so if it leaks, that's proof he hasn't done it right, and he needs to fix it?

Andy

He only fitted a new boiler, and I assume converted the system to sealed at the same time? Could well be that part of the existing system leaks, and has done for ages. Mind you, one would think that losing a litre or so a week would be noticable somewhere.

Topping up on once a week will be really hard to find the damp patch, IME. After checking things over and looking closely at all the rad valve glands, if all else fails, add leak sealer (eg. Fernox LS-I) to improve things.

In my experience it will always be on pipework under a newly installed laminate floor. My mate had to do and area of his laminate floor twice because of this.

I found one by waiting until heating was off for the summer (i.e. now), and then over-filling system whilst cold to get it up to the normal hot running pressure. This will cause maximum rate of leak, and with the system being cold, it doesn't get to dry up before being noticed.

Mine was a failed O-ring in a radiator blanking plug. With the radiator cold, water actually managed to run down to the floor where it was noticable.

Hello all

I thought I should clarify something here as some of the replies seem to point to the posters thinking I have installed the boiler myself.

If you read my original post you will see the following line is the first line:

'We have recently had a new Combi Boiler installed and it is losinig pressure'

We had the system installed through the WarmFront Grant which involved replacing the boiler, all piping in the airing cupboard and removing the tanks in the airing cupboard and in the loft so it was basically a new central heating system that was installed.

I hope this will clear up any confusion.

Kevin