C/H Pump went bang

[gazz01]

Can anybody assist in explaining how to drain my C/H system. I do believe I have an immersion cylinder with a metal coil inside which warms the water. A 22mm pipe comes from the top of it, whilst the C/H pipes enter from the side. I have a header tank in the loft, old Baxi boiler, run by a British Gas timing system(with no manual). I can only see one actuated valve to what it's doing I'm not sure. I will have to remove the leaking shut-off valves above and below the old pump, so isolation might be a problem.

 

[kostello]

somewhere near the bottom of the system, usually near a radiator is a drain off cock.
shut the ballcock by tieing it up with a bit of string.
attach a hose pipe to the drain cock and undo the little square nut. not too much as it will come right out if you're not careful

aleks

 

[gazz01]

Thanks Kostello,
fitted new pump last night. Spent time bleeding system of air (a little still flowing round the system). I woke this morning with hot water and warm house but it seems that the thermostat is being ignored to a certain extent, what I mean is the boiler is switching in and out but keeping the house alot hotter than stat is set to. Any clues??

 

[masona]

Could be a built-up of dusts on your thermostat causing it to malfunction ,switch off mains then blow out dusts.Also turn the pump to high setting and turn down the boiler stat down slightly.

 

[gazz01]

Thanks for the reply. It wasn't the stat it was the motorised valve sticking open. Can anyone help with something else. I have fitted new valve and the system now works and responds to the room stat correctly. The problem is that I only have one valve in the system which isolates the C/H and water but the wires that come from the programmer confuse me. There is 4 wires coming from it Earth, Blue, Yellow and Red. Which one is for cylinder stat, which one for C/H stat and which one is spare.