Freezing house, drained system to change valve now rads cold

[seco services]

where your mot valve is one side to heating other side to cylinder is their any bleed valves their ?
and have you bled them ?

if your pump is below the mot valve i wouldn't say the pump is airlocked.
i would say its around the mot valve being the highest point.

 

[DIYOY]

I dont know if they are bleed valves or just isolation valves to facilitate removing the pump because there are small square ends (6mm square) which you could turn with a little spanner

 

[seco services]

leave them two either side of pump they are valves that close to change pump.
if you didn't touch them leave them.

up near the mot valve is their any stubby pipes with bleed valves on ?
or near cylinder.

 

[DIYOY]

No there don't seem to be any bleed valves. There is some sort of copper venting device about 40mm round at the highest point but no bleed valves on it, I think its automatic? It is on a T piece from the 22mm pipe going into the HW tank, but you cant actually do anything with it

 

[seco services]

sounds like an auto bleed vent but they do block and it may not be working.

did you try hw and heating and nothing got hot ?
ie the flow to cylinder hot return out of cylinder cold ?

 

[DIYOY]

I was checking rads most of the day and they never got hot but I didnt check the HW - there was a tank full of hot water from Economy 7 so I wouldnt know if there was any heat from the boiler.
I'm going to try and post a photo of the setup if it works - it might make more sense to you than my attempts at describing it!

 

[seco services]

go on then.

 

[DIYOY]

I'm just loading it onto the laptop!

 

[LeedsPlumber]

Removing air from open vent system is a pain at times. Try turning the boiler on for a few seconds then off and you will hear air gurgling repeat again and again and again untill the air works its way out.

 

[DIYOY]

At least the pump has cooled down now! Sorry the camera is taking a while to load - I forgot it had about 500 pics on!

 

[seco services]

we don't want 500 pics.

try it in hw/heating.
sometimes it just as easy to slacken a mot valve joint and let any air out.

 

[DIYOY]

Hi Leeds Plumber, thanks for joining in - this is my first time using this site and you guys are being really helpful. Be back soon with a pic I hope if I can post it ok!

 

[DIYOY]

re
try it in hw/heating.
sometimes it just as easy to slacken a mot valve joint and let any air out.

Sorry to be a bit thick - how do you mean try it in hw/heating?
Dont worry you wont be getting 500 pics

 

[seco services]

hw/heating on at programmer and both stats up.

if you refilled the system and the mot valve has always been closed on the hw the cylinder coil will airlock sometimes.

 

[DIYOY]

Thanks for help & support, gave up late last night in a cold house. This morning managed to bleed air from the auto-bleed valve by swapping from HW to Htg and back repeatedly as each time i did it i could hear a hiss of air. Got most of the rads hot this morning, some prob need bit more bleeding. Got to go to work now! Thanks again.