Scratching my head with an Intergas !!!

[goz666]

Got the call from a mate who has never been near one, got there boiler losing pressure, checked for leaks and cant find any anywhere on the system. No water coming from PRV outside.

Filled up to 1.5 bar and closed the F&R iso valves, stood there and watched it drop from 1.5 to 0 bar in approx 20 mins.

The expansion vessel and fill loop are on the other side of the iso valve so are isolated off, Ex vessel is remote.

Looking for internal leaks....none, removed condense pipe and lower condensing unit to check for leaking from heat ex....none.

Removed PRV pipe and still no leaking, filled up to 1.5 numerous times and still dropping to zero so filled up again to 1.5 and pump opened, small hiss and a teardrop of water from pump and back to zero.

Now scratching everything, still losing pressure and on to Intergas technical. He suggests ex vessel, and everything else I've checked, but is adamant it is not the heat ex, which I agree because there's nothing draining or dripping from it. So, finally we're down to replacing the pressure switch ???? which I've already tried to clear out, before i go ahead and order one has anyone else ever come across anything on these ??

 

[nysk2008]

did u also disconnect condense and check no leakage there? soz if you did- are there any underfloor pipes that could have corroded and started to leak, any other signs of leakage around the appliance?

 

[nysk2008]

also does it drop when when running or cold?

 

[goz666]

I isolated the rads and pipework off as soon as I shut the isolation valves, and its maintaining at 1.5 bar in the system. So in effect on the lower side of the shut valves there's 1.5bar and above the valves (boiler internals) there's 1.5 bar that then drops to zero, if i open the flow or return isolation valve it immediately jumps back to 1.5 bar. And it's doing it hot or cold but obviously when hot is over 2.1 bar then dropping.

 

[kris]

Nysk i think hes saying it drops when the boiler is isloated so leak or press drop is at the boiler , Id shut hot n cold aswell , well cold anyway if fill point is at boiler ( is it ) ??? NRV failed if fill point is at boiler and passing that way, ( if cold water press crap) , You said you cleaned out press point was there alot of dirt, basically test it b4 you order one ,, pressure it up to 2bar then slowly slacken nut on either flow or return ( boiler side of isolation obviously) to check leak pressure then tighten back up, wait 20 mins till pressure drops to 0 then simply slacken the same nut and youl know with what you see if press is still up faulty press sensor, if not hit boiler with 4lb hammer
Not had anything to do with intergas what kind of heat exchangers are they ?

 

[Billy Bob Bob]

I isolated the rads and pipework off as soon as I shut the isolation valves, and its maintaining at 1.5 bar in the system. So in effect on the lower side of the shut valves there's 1.5bar and above the valves (boiler internals) there's 1.5 bar that then drops to zero, if i open the flow or return isolation valve it immediately jumps back to 1.5 bar. And it's doing it hot or cold but obviously when hot is over 2.1 bar then dropping.

tad confusing are you saying with boiler f+r isolated boiler cant hold pressure and its dropping strait away? if so,and prv is not leaking can only be the main hex is water coming out of the condy pipe when the boilers cold?

 

[mfgs]

Got to be the heat exchanger leaking and going down the condense as has been said.

 

[goz666]

Exactly has gasman said, flow and return isolated also cold water isolated pressure is dropping to zero. Yep, I thought heat exchanger but have removed the whole plastic unit which runs into the condense pipe and wiped dry, charged up to 1.5 bar and there's nothing coming from heat exchanger.

 

[goz666]

https://www.google.co.uk/search?q=i...s%3A%2F%2Ftwitter.com%2F4movingparts;640;1136

I have removed all of the black plastic parts from the flue downwards, under the heat exchanger and also removed the condense unit underneath.

 

[Atouchofgas]

How have you ISO flow/ return? could they be passing?

 

[goz666]

How have you ISO flow/ return? could they be passing?

Yep, isolated both which leaves the rest of the system full and still pressurised to 1.5 bar. Hence if the valves were passing then I wouldn't be getting a drop on the boiler. Similar to let by test mate.

 

[Atouchofgas]

How do you know the rest of system is full? Just to be sure why not put one new ISO on flow with gauges above and ISO on return with gauge below. This will tell you for definite

 

[goz666]

How do you know the rest of system is full? Just to be sure why not put one new ISO on flow with gauges above and ISO on return with gauge below. This will tell you for definite

Boiler is upstairs mate, highest point in system and I've already been round and bled all the upstairs rads and bled the air bleed on the boiler before I did anything else. Then when I isolated the boiler using the isolation valves I let the pressure drop to zero, soon as it did I opened the valves up and the system pressure refilled the boiler. Just to add this is a digital readout for the pressure gauge and not a manual one.

 

[Atouchofgas]

I am not disputing what you have done, been there myself. But by doing what I suggested it will then be proof that it will be either the boiler or the system

 

[Nostrum]

Very weird!

If you've found a dodgy hex then you've ruined their '18 years and no failures' campaign!

Is it on a jig or with a robokit? - ignore this just re-read your first post!

 

[Simon F]

is the pressure only being lost according to the display on the boiler?
or is the system losing pressure and needing to be topped up (with boiler connected)?

so you have isolated the boiler and have the drop, but there is next to no volume/pressure there, just the pipes in the heat exchanger, is the manual air vent passing?

 

[Ermintrude]

Nysk i think hes saying it drops when the boiler is isloated so leak or press drop is at the boiler , Id shut hot n cold aswell , well cold anyway if fill point is at boiler ( is it ) ??? NRV failed if fill point is at boiler and passing that way, ( if cold water press crap) , You said you cleaned out press point was there alot of dirt, basically test it b4 you order one ,, pressure it up to 2bar then slowly slacken nut on either flow or return ( boiler side of isolation obviously) to check leak pressure then tighten back up, wait 20 mins till pressure drops to 0 then simply slacken the same nut and youl know with what you see if press is still up faulty press sensor, if not hit boiler with 4lb hammer
Not had anything to do with intergas what kind of heat exchangers are they ?

Hex is just like in a ferolli domi compact

 

[goz666]

I am not disputing what you have done, been there myself. But by doing what I suggested it will then be proof that it will be either the boiler or the system

I might end up doing just that mate !!

 

[Ermintrude]

Test the pressure transducer. It sounds flecked to me. Pressure causes resistance to change if it's pressurised and at a constant pressure it's resistance should remain

 

[goz666]

Test the pressure transducer. It sounds flecked to me.

What and where mate ?

 

[goz666]

I take it you mean the pressure sensor, Is there any way of checking this sensor ???

 

[Ermintrude]

Pressurise it measure it's resistance? Or just fit a wet gauge on pipework?