Central heating issues

[Lucy]

Hi, ever since I turned off my hot water water to plumb in a new basin, I've had dramas with my central heating. I turned off both the stop-cocks in the airing cupboard... I'm now assuming one was for the hot water and the other was for the heating system. Now when I have both the hot water and heating scheduled to come on at the same time, two of my radiators don't get hot. I have to turn off the hot water, which sounds like it makes a pump kick in, then the other two get hot too. I have a Draton mid-point actuator and a Grundfos pump. Any clues about what's wrong would be greatfully received.

 

[SimonG]

Shouldn't have had any impact on your heating. Any pics of the airing cupboard and what you turned off?

 

[Lucy]

Unfortunately I don't have a camera until Christmas day lol, but it was two red taps. One of them had no effect on the hot water but the other did. I'm not sure if this may be linked to the issue or a separate problem but the lounge radiator (one of the two that doesn't heat up when the hot water's turned on) has been getting very slow at heating up, even when I turn the hot water off, and even then it is stone cold at the bottom. Tonight it's doing nothing at all, even at the top :-(

 

[SJB060685]

As above Lucy.
Are you saying you're turning off the HW at programmer to get last rads hot?
Are they upstairs rads or downstairs?

 

[Lucy]

Yes, I have to turn off the programmer.
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One is upstairs, and heats up really hot straight away when I turn off the HW. The other is downstairs and is very slow to heat up and doesn't heat well at all when it does get going. They're both the same side of the house and are the only two rads on that side of the house. All my other rads are on the other side of the house and are absolutely fine.

 

[SJB060685]

Were they ok before your basin install or always a problem?

 

[SimonG]

Did you re open the red handled valves fully? Does one just keep on spinning?

 

[SJB060685]

Did you re open the red handled valves fully? Does one just keep on spinning?

What you thinking Si, not enough water in system? That's one thought I had

 

[Lucy]

The lounge rad was always a bit slow to heat up but it's only since I put the basin in that I've had the problem with having to turn off the HW to get it to heat up. I'm wondering if I maybe need to flush out the radiator then balance the system. But it still leaves me with the problem with the HW. It's not really a major problem because I can always stick the HW on in the middle of the day for as bit while the heating's off, but I'd like to know why it's happening.
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Yes Simon, I've opened them both to the max and they both reach a point where they stop turning.

 

[SimonG]

What you thinking Si, not enough water in system? That's one thought I had

Aye, one was heating cold feed and the gate valves snapped closed.

 

[Lucy]

I don't know if this would have anything to do with it, but when I first moved in 2 summers ago, even though the heating was switched off, every time the hot water came on (as programmed), the heating would come on too. I had a plumber out to look at it and he said that the motorised valve was working fine but for some reason the hot water was back flowing into the heating system. He ended up putting a valve in one of the pipes under the floorboards just outside the airing cupboard. It's fine since then, until I messed with the stop-cocks.