Progress (I think!) There is one LED on and reading through the manual fault finding guide leads to either the air pressure switch or PCB. Unfortunately it doesn't give any indication of testing either one so I will have to try both. Hopefully this should resolve it, although the pessamist in me is not optomistic!!! I'll report back in a few days. Thanks for all the help (so far!)
Dean
If your air pressure switch is like mine, it's just a switch which closes when the fan generates a high enough pressure. If you suspect that it's not closing when it should, you can test it by temporarily bridging its contacts. If the boiler *then* fires, it means that the problem is in that area. Don't leave it bridged, though!
If the pressure switch doesn't operate, it could be a duff switch, or a pipe might have fallen off, or the fan may not be running fast enough to generate the required pressure.
[Apologies for starting a new thread - OE is playing silly B'e with the old one!]
Slightly inconclusive then! Whatever was tripping the RCD before now isn't for some reason - but you don't really know whether it was the boiler ot the pump.
The boiler is cycling because it is producing heat faster than it is being taken away. Remind me where all this started - did you have lack of circulation due to a supposed air-lock?
During the 10 minutes when the boiler was on, did the radiators get hot? Have any/all of them got TRVs on and, if so, are they fully open?
If there are no TRVs and no airlocks, and all the radiators are turned on, the room stat is fully up, and the pump is working properly (a lot of 'ifs'!) I would expect the boiler to fire continuously until everything is hot.
All TRV's have been taken off, All radiators are full. Room stat up, pump running. When I ran it for 10 minutes some of the the radiatiors were getting hot. Can a pump run slow? It is on its maximum speed at the moment, but i have no idea how efficient it is, plus this doesn't solve the fact that no power is coming from the boiler to power the pump. So i fugure either the pump was not efficient enough and something went in the boiler to stop it supplying power to the pump or something is amiss in the boiler. There is the question of an led on when the boiler shuts down. I will try Glowworm Technical this morning to see if they can shed any light.
Dean
Pumps can sometimes lose part (or all!) of their impellor - which makes them rather less efficient!
You could still have an air lock in some of the radiator supply pipes, even though the rads have water in them. You could try closing the valves on those which *do* get hot in order to try to force some water round the others. This may clear any air at the same time. The other thing you can do is to bleed a *lot* (several pints) of water out of each rad - first with one valve open and then with the other - but not both at the same time. This will ensure that *both* flow and return pipes are clear of air.
There may well be a fault in the boiler - unless there is an RCD trip for it's pump supply, which could have tripped? You could ask GW Tech about that, perhaps.
Spoke to Glowworm technical who advised it is the PCB. Ran the pump on its own all day and the boiler was coming on and off, but got heat to all the rads. I'll try and get it refurbed and let everyone know! Although I am still concerned that something may have brought on the fault e.g. inefficient pump?
Dean
Do you mean the link from 9 to SL?
Does this diagram extend further to the left, to show any internal connections? If so, can you scan and post this bit?
So I woould deduce that the boiler stat/air pressure
It looks as if 9 should be permanently live (via link on LHS of block). You should have *either* a link from 9 to SL (which makes SL permanently live)
*or* an external switch/timer/whatever between these two points. If the timer gets its live feed from somewhere else, it doesn't *have* to come fromSorry, not quite sure what the photo shows - so I can't comment on that.
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