Central Heating Problems

[ricarbo]

You didn't say if the pins in the thermostatic valves go up and down. Do they?

 

[ChrisR]

Assuming the valves are open, it sounds like a major sludge problem.

 

[DIYNOVICE82]

You didn't say if the pins in the thermostatic valves go up and down. Do they?

Sorry for sounding dumb but i dont know what you mean!!
Can you explain in 'simpleton terms'?

 

[ricarbo]

Yes, the pins. If you can take off the head of the valve (the bit you turn), you are left with the brass or chromed brass body of the valve attached to the pipe and the rad. This will have a small pin (about 1 or 2 mm diameter) sticking out of it, in the centre of the body, directly under where the head was. it's the pin being pushed in by the moving part of the head that turns the rad on & off. There's a spring inside the body of the valve that should push the pin outwards. the pin can be stuck in the off position (perhaps because the valve has been closed for months). It depends on the make of valve of course but a pin that only sticks out say 2 to 4 mm is probably stuck in the off position. It pops up about 5 to 10 mm more to go to the on (valve open) position. The spring pushing it open is quite strong, so you need to put something over it (50p coin?) to spread the pressure on your thumb, so you can try pushing it in repeatedly until it (we hope) becomes unstuck and pops up. If it doesn't free off, a more drastic way to free it is to close the other rad valve, then remove the thermostatic valve from the rad, put a small screwdriver into the waterway and lever the valve open. You can do this without draining the system if you are foolish/brave/well prepared for the flood of black water that will permanently stain everything it touches. Probably better to be sensible and drain the whole lot first, you've got several to do and have already lost all or most of your water treatment (if there was any to start with) by your excessive 'bleeding' operations. If the valves are old and were found stuck, I'd replace them because i hate things that don't work. I'd probably replace them with the same brand as existing so as to avoid having to alter pipework. Once I got everything working, I'd add some flushing agent eg Sentinel or Fernox, circulate it hot for a week or whatever it says on the bottle, repeat until the water drains out clean, then refill with inhibitor (same brand as flushing agent). Personally, I'd prefer to do this instead of employing someone to 'powerflush' the system, because i'm a cheapskate. hope this helps