is this a big job

[norlandd]

Combi system loosing pressure. After checking obvious Corgi man reckons its expansion vessel problems. I have to re-pressure twice a week with engineer reluctant to sort out. Heating engineers are not two a penny here and would have difficulty finding alternative engineer. System is Glowrom Swiftflow 7 years old.

My question is: Is this a big job and probably the reason for his delay in recifying problem. Boiler is situated in an awkward situation 7ft off the ground

Cheers

 

[kevplumb]

you can put a replacment vesssel anywhere on the system as long as it has an open path ie no valves
leave tho other one in place
not a big job really

 

[ArtfulBodger]

I have to re-pressure twice a week with engineer reluctant to sort out

Are you re-pressurising using the filling loop or are you recharging the pressure vessel?

 

[kevplumb]

would think if the pressure vessel twice a week he would have had a pump full of water by now

 

[ollski]

If he cant fit the expansion vessel anywhere else or if the current vessel is leaking then yes it is a big job....basically the whole boiler needs to be stripped down as the vessel is right at the back. Is the PRV definitely not leaking?...swiftflows are notorious for blowing the prv at 3 bar even when the cold system pressure is only set to 1. I normally leave them at .6 bar and they work happily at that. I've had a few leak from the auto air vent aswell in the combustion chamber....presuming he's checked that?

 

[norlandd]

Thanks for all the comments. When engineer comes (hopefully this week) I shall have to, tactfully, mention the other possibilities. I shall come back with outcome.

Cheers

 

[norlandd]

update.

For the first time noticed water from vent pipe (prior to engineer's latest visit). He asumed it was PRV problem and has installed new one. Unfortunately still loosing pressure and wet /damp vent pipe evident. Presumably therefore must be EV. Hopefully he will attned to this over next week or so.

 

[ChrisR]

We still don't know, has he repressurised the pressure vessel with air? He should have done and it shouldn't take long at all (once he's found where the valve is!) It's usually done with a car foot pump.
If he hasn't , you will keep losing water and having to refill.

 

[norlandd]

I have read back to find out the principles of the EV but still not too clear. Can low AIR pressure in the EV cause a WATER pressure loss in the system.
Sorry if its a daft question

 

[kevplumb]

causes exess pressure in the system when the water gets hot it expands and has nowhere to go
so the pressure goes up and blows out of the prv

 

[norlandd]

cheers

I'll have to make sure engineer has checked air pressure first before going feet first and replacing EV

David

 

[norlandd]

heating engineer called
Has now
changed PV
checked air pressure in EV (no water in air section)
BUT vent still leaking and when heating is on presssure goes up from 1 to 2+.When heating is off pressure will come down and will eventually become zero
He is mystified. What can I tell him?

 

[ChrisR]

The hose or pipe which the pressure vessel connects to is blocked with sludge/scale. A bit embarrassing?

 

[kevplumb]

dont you ever sleep
good point tho

 

[norlandd]

Update

Plumber has now fitted 'stand alone' expansion vessel. System working fine. Has been heating engineer for 30 years+ and tells me that this is only the second EV he has had to replace.I find this strange, as reading this forum I assumed it was a fairly regular occurance. Is this the case?

Found the contributors of this forum to be excellent.Well done. I am now a regular reader - not good enough to be a contributor.

Cheers
David