On 15/03/2019 12:51, Tim Lamb wrote:
In message , Mr Pounder Esquire
writes
John Rumm wrote:
So far all the normal tricks don't seem to be doing it!

Short version:

There is a leak somewhere in my central heating system - its losing
pressure regularly, and needs topping up with at least a couple of
litres a day.

Snip. Not being rude.
I was losing water. The loop valve was not turned off properly, even
though
it looked okay.

Further news on my leak.

I think I have found mine as well....

Having finally got access to all the ground floor pipework (lifting
floors etc), I found - erm nothing!

So today while the heating was on setback I decided to make some checks
on the boiler itself. Lifted its pressure to about 1.5 bar, and then
turned its power off. I thought that I would also check the condensate
drain. Interestingly - normally its spotlessly clean and full of clear
water. This time it looked decidedly orange and slightly scummy. So I
emptied and cleaned it and put it back, then left it alone for a couple
of hours. Had a look again and its now 3/4 full of water. Emptied again,
left another hour or so, and verified that the system pressure had
fallen a little. (I replaced a rad vent plug with a larger pressure
gauge to be able to more clearly see the difference without the aid of
the boilers electronic gauge).

So the good news is at least the plumbing is ok, and I have not got to
fix something in some awkward difficult to get at place. The less good
news is it looks like the primary HEX mush have a small internal leak.

Quite how/why that happened on a 7 year old boiler on a well cleaned
system that was always treated with inhibitor I am not sure. I suppose
until I look in the combustion chamber its hard to say what is going on.

Replacement HEX seem to range from £120 for a reconditioned one, and new
ones ranging from £220 - £450 depending on where you get it.

Now I know its not leaking water into the house I may just slap in some
more inhibitor and leave it until the warmer months!

Isolating the floors showed the leak was upstairs! Slight wet patch
showing below the manifold cover.

Water drip from the *plumber fitted* mixer valve! Basically the threaded
spigot on the valve was too short to seal against the fibre washer
inside the 22mm coupler. The joint was garmed up with plumbers mait.

Agricultural solution plus lots of ptfe tape...... we'll see how it goes.



--
Cheers,

John.

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