Central Heating Leak

50Twuncle

Our plumber has been - topped up boiler (again) .
Told us to give him the pressure tomorow
He will isolate upstairs to prove leaking zone
Then lift floorboards - if boiler loses pressure ( which it will)
More tomorrow

macman

Sorry, but you need to get a new RGI-what is the point of repressurising (which you can do yourself in one minute)? You already know it's losing pressure.
This is the same guy who didn't even check the PRV overflow pipe first time out?

keystone

50Twuncle wrote: »

Our plumber has been - topped up boiler (again) .
Told us to give him the pressure tomorow
He will isolate upstairs to prove leaking zone
Then lift floorboards - if boiler loses pressure ( which it will)
More tomorrow

Please don't tell me that you have told him (or even insisted) that there has to be a pipework leak and that he's bought it? You've been pushing that agenda almost since day one despite what anybody else has told you.

My gut feel is still think that your leak is within the boiler casing and the fact that the boiler has dumped a load of water this morning is a further indication that this is the first place that should be looked at. But hey no can't be bothered to do the simple HEX test because that doesn't fit with thee "it has to be the pipework" theory.

Sorry to be snarky but I've run out of patience with this one.

Best of luck with it. Tell us what he finds. I have a hat available for consumption if necessary.

Cheers

50Twuncle

For you unbelievers out there :

I know that I am correct in thinking that the leak must be from the pipework
Our plumber/gas engineer topped up the pressure yesterday to 1.5 bar - there is apparently a leak in the topping up valve - a seal has gone ("somehow" - temporarily cured by leaving the key in place !!) - This appears to be a temp fix.

Since yesterday (at 5pm) - we have lost 0.5 bar of pressure in the system - and no more water has come from the boiler casing.
The unit is mounted on the kitchen wall so and has nothing around it to block the view of any leaks.
The boiler has been unused (even the pre-heater is off) from 10pm last night (when the pressure had already dropped to 1.3 bar) - and yet, this morning - it was 1 bar - with no leaks from the casing - So the water has only one place to go - out of the pipes.
The PVR outlet is still dry and clean.
Explain that....
Today - he intends to cap off the pipework to upstairs and re-pressurise the system to confirm that the leak is downstairs (Which we are 95% sure it is anyway)

keystone

So the water has only one place to go - out of the pipes.

Ye gods and little fishes. No It doesn't. Just because there is no water coming out of the PRV pipe doesn't mean that there isn't a leak inside the boiler between the two sides of the heat exchanger or elsewhere internally. Is there any way that I can make this any clearer for you?

Thats like saying theres no condensation coming out of the exhaust of my car this morning like there is every other morning so the presence of that filthy coffee coloured stuff under my radiator cap can't possibly mean that the head gasket is anything but OK.

Cheers

50Twuncle

keystone wrote: »

Ye gods and little fishes. No It doesn't. Just because there is no water coming out of the PRV pipe doesn't mean that there isn't a leak inside the boiler between the two sides of the heat exchanger or elsewhere internally. Is there any way that I can make this any clearer for you?

Thats like saying theres no condensation coming out of the exhaust of my car this morning like there is every other morning so the presence of that filthy coffee coloured stuff under my radiator cap can't possibly mean that the head gasket is anything but OK.

Cheers

OK - From what I understand - we are losing the amount of water from our complete central heating system - to reduce the pressure from 1.5 to (presumably 1 bar (even though the meter shows 0 bar)) in 24 hours
That is a fairly large amount of water - proven by the 10 seconds plus that the valve is opened for to refill it.....
Now - all that water must go somewhere ?
It is NOT disappearing into thin air..
It is NOT getting out through the PRV outlet
It is NOT leaking out through the fill valve (any more...)
So where is it going to ?
You keep on about the heat exchanger leaking - but where would the litres of water go to if the heat exchanger was leaking ?
Would it drip down through the case ?
There are no drips (even small drips) in the case....
My only nagging question is the white plastic (overflow ?) pipe that disappears behind our draining board and is connected to the drain ??
Could that be where any water goes ?

Mr_Ted

Yes it could be draining through the condense pipe;)

If your ?Plumber? is going to the extremes of cutting pipes then there is also no reason why he should just cap them?
He could cap one and use the other to fix a test rig & gauge and do a pressure test without filling the system and leaving it?
It can be tested by filling with water and pressuring with air from a foot pump to twice the normal working pressure with no problem and it will give a result of a pressure drop in minutes on the gauge{hydraulic test, should be done normally on new system after 1st fix and can be done on old systems so not uncommon for a skilled ?Plumber?)

It wont show you where the water is going if there is a leak, but it will prove there is a leak;) then your ?Plumber? can isolate other sections of the system to establish further exactly where it is, its not rocket science and it will take forever keep watching the boiler pressure gauge every time

A little time and effort rather than coming and goings are the way to go

macman

Is he intending to charge a call-out fee for each of these visits when he turns up, but doesn't actually do any fault-finding at all?

50Twuncle

macman wrote: »

Is he intending to charge a call-out fee for each of these visits when he turns up, but doesn't actually do any fault-finding at all?

No - no charge yet !!

keystone

50Twuncle wrote: »

You keep on about the heat exchanger leaking - but where would the litres of water go to if the heat exchanger was leaking ?

OK then I didn't make it clear then - sorry. The heat exchanger is where the heat from the burner heats the water for both the CH and the DHW. As there is only one burner then this ahppens in the same place. But as you don't want to mix your CH water with your DHW water the HEX it has two halves and by design CH and DHW are kept separate. If, however, there is corrosion within the HEX and the CH side has now become joined to the DHW side through one or more holes generated by that corrosion it will leak from the higher pressure side to the lower pressure side. The pressure will fall. A fall in pressure doesn't mean it has dumped ALL its water. You are looking at a lot less water than you imagine to drop the pressure from 1bar down to zero.

The valves already discussed are in place to be able to isolate the boiler from the remainder of the system. So why not do it and then prove whether its the boiler or whether its elsewhere. If its elsewhere then at least the boiler has been eliminated. Thats why I keep "going on" about it.

Cheers