boiler keeps getting air locks, why?
Discussion
Apologies for continuing the thread, but we had a similar issue before Xmas and I'm intrigued....
So he shorted the boiler stat and crowded hot water through the primary on the HW cylinder (I assume that's what is meant by 'boiling the cylinder'?). Which, if you got hot water suggests the primary flow to the cylinder is not sludged up? Which then suggests the problem could be as simple / cheap as a duff motorised valve maybe? Probably not helped by poor pipe routing into the cylinder. (Which having seen it is probably why your plumber has condemned most of it)
We went through all these possibles when our system produced no 'boiler sourced' HW- our problem turned out to be a completely sludged CW supply to the primary circuit on the HW cylinder- we couldn't get any HW through the cylinder primary at all.
Unless your boiler is on its last legs and/or you are dead set on changing it I'd be inclined to tidy up the pipework / valves etc first and see what occurs. Bolting a new boiler onto an existing system could possibly throw up more issues (especially if the original install was a bad as it seems). But then I'm a cheapskate (hence, no Fernox in our system and the resultant sludging
)
So he shorted the boiler stat and crowded hot water through the primary on the HW cylinder (I assume that's what is meant by 'boiling the cylinder'?). Which, if you got hot water suggests the primary flow to the cylinder is not sludged up? Which then suggests the problem could be as simple / cheap as a duff motorised valve maybe? Probably not helped by poor pipe routing into the cylinder. (Which having seen it is probably why your plumber has condemned most of it)
We went through all these possibles when our system produced no 'boiler sourced' HW- our problem turned out to be a completely sludged CW supply to the primary circuit on the HW cylinder- we couldn't get any HW through the cylinder primary at all.
Unless your boiler is on its last legs and/or you are dead set on changing it I'd be inclined to tidy up the pipework / valves etc first and see what occurs. Bolting a new boiler onto an existing system could possibly throw up more issues (especially if the original install was a bad as it seems). But then I'm a cheapskate (hence, no Fernox in our system and the resultant sludging
) 
the primary flow from boiler should rise all way from boler to cylinder the slightest backfall and the system wont gravitate and complete circuit any run vertical should rise .ideal senario is airing cupboard above boiler primary straight into cylinder if primary run across floor then slight fall back if you know what i mean you to over come this and turn it to fully pumped system providing its not a primatic cylinder if this sounds like double dutch then your plumber mate should explain
dave144 said:
How do you short the stat? I wasn't around when he sorted it.
As you say I don't think there was any sludge in the system but because the cold water tank isn't high enough above the cylinder it will keep drawing in air. The tank is as high you can go, so where to got from here??
you got a backfall in the flow pipe make it rise to cylinder problem solved telling you As you say I don't think there was any sludge in the system but because the cold water tank isn't high enough above the cylinder it will keep drawing in air. The tank is as high you can go, so where to got from here??
eskidavies73 said:
the primary flow from boiler should rise all way from boler to cylinder the slightest backfall and the system wont gravitate and complete circuit any run vertical should rise .ideal senario is airing cupboard above boiler primary straight into cylinder if primary run across floor then slight fall back if you know what i mean you to over come this and turn it to fully pumped system providing its not a primatic cylinder if this sounds like double dutch then your plumber mate should explain
Hic!
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