Re: Central Heating
 

Yea, check there is a spark at the plugs too. Just hold it down to the bodywork...

Re: Central Heating
 

Stuck valve?

Our system went TU earlier this year. Got a fixed-price repair from BG which seems good value at the time.

Shame that the flue had gone so the boiler needed mending anyway :-(

Got a nice new, quiet, efficient condensing combi now..... miles better than the old Worcester/Bosch 240.

Re: Central Heating
 

hi, on the side of the pump the black part, you undo the cover and with a multimeter see if there is 240v when you have the heating on if you have voltage but pump not running, pump=fubar. if you don't have 240 then then it is possibly the zone valve which is the silver box on the right of your picture, is will say honeywell on the cover.

Re: Central Heating
 

Have you tried turning it off and on again ?

Re: Central Heating
 

Update:

Heating's been on for 10-15m now and all the upstairs rads are searing hot, the downstairs rads aren't, of the three one is hot all the way through, the other two (the bigger two) are warm at the top but almost cold at the bottom, thinking it could be an airlock somewhere perhaps? Bleeding attempts result in inconsistent pressure from the two bigger rads

My google-fu tells me that black switch on the pump is just a speed setting, and my investigative wiggling would agree, the pump also fails to respond to the thermostat when it would normally switch off as well, meaning the pump is just running constantly now...

Re: Central Heating
 

sounds like you have an airlock stopping the down rads getting hot, turn off the upstairs ones to force the water to downstairs, alternate the pump speed between 1 and 3

Re: Central Heating
 

+1

Re: Central Heating
 

Thanks for that:thumleft:

The pump is running, it's hot and humming away so I assume there's power coming to it? The speed switch appears to be working fine as the pump noise lessens as you'd expect on the lower settings. I can check the voltage if you like, I assume it's safe to do so while the pump is active?

The problem appears to be that the pump doesn't respond to the imput from the thermostat, when it clicks ON the pump doesn't switch on and when it clicks OFF the pump doesn't stop


Oh, and LOL @ fizz:p:mrgreen:



EDIT: will try doing what you guys suggest in posts #16 &17 and report back:cool:

Re: Central Heating
 

intermittently tun the programmer ie htg and hw both off to allow air to rise up the vent pipe, if there are vent in the cylander cupboard to clear any air the ones that you vent with a radiator vent key then keep bleeding these, if it is airlocked there is no set way to clear it, everybody does there own way, one of our guys been in the job 30years swears by washing up liquid in the system to beak down the air.

Re: Central Heating
 

if the pump is running there is no need to check the voltage, so you can leave that alone.