Hot water but no central heating

[TryItTom]

Hi

I have hot water, and the boiler fires up to replace it when I use the hot water, but I have no central heating.

I have put the boiler to max, the heating thermostat to max, and CH and HW to ON on the control panel - but still only get HW and no CH.

I recently replaced the mid-position valve and the system has been working perfectly for weeks.

Any ideas why the CH has stopped working?

When the boiler fires up, all pipes around the mid-position valve are hot so I don't understand where the heat for the CH is going?

Thanks very much all,

Tom

 

[misterdubya]

Check that the pump is working. See FAQ's if your unsure how to do this.

Mr. W.

 

[adlplumbing]

and bleed your rads

 

[TryItTom]

Hi, thank you for your responses.

The pump is NOT running. It's a Grundfos selectric. I'll try bleeding it and will bleed the rads, so hopefully that will do it.

Any tips on restarting a Grundfos Selctric would be much appreciated.

There is definitely an air block lurking somewhere in the system

Regards,
Tom

 

[45yearsagasman]

You must have a y plan system.Is the pump running when HW is calling.If so then its not the pump but a fault elsewhere.

 

[TryItTom]

No, the pump doesn't run when the hot water is being called.

 

[TryItTom]

Hi all

Thanks for your help again.

Problem seems to be fixed and both CH and HW are running. I cranked up the motor to speed 3 and opened one of the valves and it sparked into life.

Motor now running on speed 2 and all is well.

Now to find this air lock.....

 

[Agile]

It sounds as if you had left a pump valve closed?

One wonders why you had closed the valve!

 

[TryItTom]

I think the best answer I can give for that is that I bought the house in July after it standing unoccupied for 6 months.

Someone must have decided to go round and close all valves.

I've been very busy since we moved in, as you can imagine. It's a steep learning curve but oddly enjoyable.

Just for my own sanity, both valves either side of the pump should be open - correct? and what it 'open' when both are stiff?

 

[Agile]

They usually turn for about 4-5 turns but 90% of the opening is in the first two turns. You should fully open them and then turn back 1/4 turn.

They will not turn beyond fully open or closed.

If they are too tight then loosen the gland nut on the spindle but retighten them when you have finished adjusting them.

Tony