Tricky airlock on gravity HW circuit - advice needed

[EliteHeat]

I have a customer who has a profile with gravity HW and pumped CH. The gravity circuit is easily the worst I have ever seen:- 3" above the boiler is has an elbow, another 3" along it has another, then a further 3" and yet another, then the 28mm disappears from sight.

The hot water cylinder is installed so the 28mm F&R pipework is entirely inaccessible unless I am prepared to dislocate both shoulders and grow two new arms. There are no vents, automatic, manual or otherwise on the system except the open vent. The cold feed and open vent are both in 15mm and connect to the flow and return on the gravity side.

After installing a new radiator the hot water circuit is understandably airlocked and I need to sort it out.

My only thoughts at the moment are temporarily withdrawing the boilers temp probe and trying to boil it out. I'm not too keen on this idea.

Any ideas anyone?

 

[ChrisR]

Try a water vac on the vent, that will suck air/water in through the feed and up the vent

Use tap flexies on the f/e tank supply to connect to the vent pipe(cos it's easier) or the feed pipe from the f/e (which is messier)

Speedfit do 22 to 1//2" hose which are handy for that too.

Saw on a forum someone using thin hose to connect between the float valve outlet and the feed pipe, shoving the hose into the holes. He used shower hose tube, the stuff which comes with a plastic T piece and rubbers to shove on the taps.

backfill through a drain cock, temp blockings on the feed and vent to make the air squash a bit, then release the bung/hands used and the air/water should rush up the feed /vent pipes. Needs spare people but quick to try IF things are arranged conveniently.

 

[EliteHeat]

Cheers Chris - I'll try those - ta