Dealing with airlocks in systems with gravity hot water

[Teggs]

Hi all,

I'm not having too much luck with m y central heating at the moment. In one of my older houses I have been having ongoing problems with the gravity fed hot water.

The system had been drained to replace a raditaor on the ground floor. Once this was done the system was refilled. However I have not had hot water since. I have drained the system twice in order to try and solve the problem but this has not helped.

I suspect it's an air lock but am unsure of how to proceed. I can not find any air vents along the pipework. The pumped central heating works fine everytime I refill the system.

Luckily the immersion is supplying hot water for the tenants but I'd prefer to sort it out.

Any advice would be greatly appreciated.

Terry

 

[pannierstan]

you might have to remove the thermostat file and what is known as boil the system to get the air out of the gravity circs.

Not really a job I would suggest you try unless you have done it before as it may well scare you to death.

Be warned. Get someone who knows what they are doing.

 

[Teggs]

I'd read on the internet about that. I'm willing to try to do this.

Is the process of disconnecting the thermostat easy?

Terry

 

[pannierstan]

Need to pull the stat out of the pocket in the heat exchanger but you didnt mention your make of boiler.

 

[corgiman]

and if you aint qualified and have never done it before

good luck

LMAO

 

[pannierstan]

and if you aint qualified and have never done it before

good luck

LMAO

Quite

 

[Teggs]

So it's another heating engineer job then? If it gets the hot water back on it's the best option.

Cheers guys, I'll get an engineer out, I'll let you know the outcome.

Terry

 

[pannierstan]

I think its for the best Terry.

If you get it wrong you will have a flood at least and a new boiler at worst

Stan

 

[Teggs]

As it happens I have a guy who does my gas safety stuff, I'm sure he'll deal with it if he isn't too busy!

Once again thanks,


Terry

 

[Teggs]

Hi again guys,

Sorry to continue my old post but I've still not managed to sort out the problem with my gravity hot water.

I got an engineer out a while back who preformed a system boil on the system and after about 15-20 mins we both heard a whoosh of water through the pipework leading past the cylinder, I presume routed to the header tank. I was told this would sort out the problem, however after 2 days there was no heat in the flow and return pipes to the cylinder.

Having observed how the system boil was carried out I did this myself, again having success for a day or so before heat being lost.

As my luck (or should I say lack of it) would have it the engineer I use is off over the holiday period so would appreciate your continued advice as to what maybe I should do.

I have checked that water is in the header tank and that there are no valves semi or fully closed. Is it likeely that I haven't carried out the system boiling proceduere for long enough?

Yours,

Terry