Help!!! No heating after changing rad valve

[flutterbye]

Now I've truly gone and screwed things up in this house. Replaced a lockshield valve on an upstaris rad using the "bung/vacuum" method.

When I remove bungs from two pipes in F+E and turned heating back on the pump appears not to be able to push the water around. I think there might be an airlock?

The rad I replaced the valve on emptied of water - so probably have a small bucket worth. Now the pipes are not getting hot Im gussing because the pump can't move the water around?

What can I do?? (Before it get too cold in here!)

 

[carlramsay]

bit confused did you bung the tank?. But you must have emptied the rad whilst changing the rad valve. If you emptied the rad you will need to bleed the rad

 

[flutterbye]

HI I bunged CH supply from FE tank and also the vent. THen I took the old valve off the rad and the water flowed out of the radiator. There was only a cupfull from the pipe side of the valve.

THen I went upstairs and removed the speedfit cap on the vent pipe and unbunged the FE tank. (I'm thinking maybe I should have unbunged the feed pipe first becuase?)

The rad is currently empty and switched off because I don't have a radiator spanner. So the valve is simply closed on both sides as it was before I went to change the valve.

Anyway, the problem is I think I've created an airlock since the pump is moving water around and makes a slightly different noise with far less "gurgling" than usual.

 

[flutterbye]

Anyone please?

 

[Hugh Jaleak]

Doesnt sound like you've lost enough water to cause a problem, cupful from the pipes, disregard contents of rad as you haven't refilled it.

Noisy pump would indicate air, have you bled the pump? When the boiler lights how far does the the heat travel through the system?

 

[tryitandsee]

If you have bled air from all places you can, ie all other rads, perhaps a bleed valve in airing cupboard and the pump bleed screw, perhaps you should drain off some water from the rad valves where you have taken off the radiator. Open each valve and catch the water in a bucket, may be an air lock that will shift from your previous drain down for that radiator.

 

[flutterbye]

MAny thanks for the replies.

Im pretty sure it is an airlock now because there is a drain valve on the return pipe to the boiler. When I open it nothing comes out! The valve looks in reasonable condition and turns faily easily so guessing there is no water in there?

I've opened the pump bleed valve. How long should I leave it open? SHoudl I try when the pump is running or always off?

A friend suggested forcing water into the drain valve by the boiler but is that only a last resort?

Getting cold and scared now!

ALso, the boiler is turning on for about 20 seconds every now and again but why would it do that if there is no water in the return pipe?

 

[Hugh Jaleak]

If system was working ok up until you took the rad off then it cannot have completely run out of water! Drain off at boiler may have a stuck washer, whilst you are opening it, the washer remains seated, hence no water coming out.

Have you water at any part of the system? Try draining some off from another point, then check it is replaced from the F&E tank.

 

[flutterbye]

Yes systme was working before hand and I'm getting water out of most of the radiators (the ones with working bleed valves!).

I tried draining from the radiator whose valve I was replacing and got about a bucket out but haven't tried draining more than that.

 

[flutterbye]

Could it be that an airlock just a bit further away from the drain valve on the boiler is stopping water coming out? ALthough suspcious that the drain valve would be totally dry.

I really don't know what else to try?

 

[Hugh Jaleak]

Have you tried running the system? If so, what actually happens. Seems a safe bet there's water in it, so should work!

 

[flutterbye]

Yes when I run it boiler comes on for about 30 seconds and then goes off then comes back on again....

Pump makes a different louder noise than before and rads fdont heat up (after 10min test)

 

[flutterbye]

Ok, I've got a bit further. The valve near the boiler was stuck - I unscrewed it all the way and took out the nut and the plug was still stuck down - bone dry.

I've now put the system on for 10 minutes, and when I open the valve near the rad I was originally trying to replace, the water is clearly getting warmer there. Howevere all the other radiators are off !

 

[WabbitPoo]

Is the header tank now empty?

 

[flutterbye]

No I didn't tie up the inlet so if I open the valve at the radiator new water pours in.

Really don't know what to do and I image calling out a plumber on Sat night ain't going to be cheap.