Can anyone please tell me...

[mogget]

edited for clarity.

After leavin the heating on only one radiator nearest the airing cupboard went warm, not hot just warm, no other radiators came on. It's like it came on for a small bit then went off??

When you open the valve manually, the boiler and pump are controlled by the HW side of the programmer, and the HW tank thermostat. It sounds like the tank thermostat has decided that the HW is hot enough, and has shut the boiler down. With the knob on the tank stat going round in circles there's no way of adjusting it.

It's fairly easy for a DIYer to replace as long as you either get an identical one, or work out where the wires go. There are three wires, one is 240V live in, then two live outs, one is 'call for heat' and the other is for 'satisfied' - that allows the heating to work when the hot water is already hot enough. Lord only knows which colours the installer has used for the wires!

 

[doitall]

Manually open the MVs and it will work.

I opened the 3 way valve but nothing!

As you haven't answered the question, I assume the cylinder gets hots but not the heating.

Therefore if you turn the hotwater and heating on then manually open the valve the rads should get hot,

 

[mogget]

It's like it came on for a small bit then went off??

Just having another look at the wiring, what is the grey wire from the valve connected to? It can't be connected to all those neutrals, surely?

 

[ToMBoY212]

Manually open the MVs and it will work.

I opened the 3 way valve but nothing!

As you haven't answered the question, I assume the cylinder gets hots but not the heating.

Therefore if you turn the hotwater and heating on then manually open the valve the rads should get hot,

Yer the cylinder does get hot but rads are still cold.

Got the HW to 'ON' and the CH to 'ON' made sure the thermo stat was above threshold, then manually switched the 3 way valve. Been an hour and no rads are warm

Gonna take the Cylinder thermostat to bits n have a look.

NB. My water from hot taps are still very hot!

Thanks

 

[doitall]

In that case you have a restriction or air lock in the pipes, but first take all the TRV heads off and check the pins are free.

 

[weseeyou]

In that case you have a restriction or air lock in the pipes, but first take all the TRV heads off and check the pins are free.

elementary my dear Watson

I presume that all the rads have been bled yes ?
Have you checked that the small `header tank' is actually filling with water and the ballvalve is working ? if you have no head you'll have no pressure to force the air out of the system.

Open all the valves fully and go round bleeding air out of all the rads. Make a note of those that do not vent. Check the bottom of the rads to see if any of the pipework or valves are getting hot. ditto the pipes near the diverter valve. You should be able to feel where the hot water is getting held up

 

[mogget]

A couple of tangential thoughts -

Is this a microbore system, (pipes to the rads in 8 or 10mm)? Is it possible that the HW circuit is 'stealing' water from the CH circuit? At the moment the valve is only doing HW or mid-position.

Is the design such that a gravity circulation is possible between the boiler and HW cylinder, in conjunction with a weak or failed pump? Thus masking the real problem?

Obviously all this would be much easier if the controls were working properly!

 

[weseeyou]

A couple of tangential thoughts -

Is this a microbore system, (pipes to the rads in 8 or 10mm)? Is it possible that the HW circuit is 'stealing' water from the CH circuit? At the moment the valve is only doing HW or mid-position.

Is the design such that a gravity circulation is possible between the boiler and HW cylinder, in conjunction with a weak or failed pump? Thus masking the real problem?

Obviously all this would be much easier if the controls were working properly!

yes its beginning to look like the pump again isn't it.
If it was running properly it should be shoving that water around lickadyspit. Boiler and first part of a ch system getting hot with boiler shut down usually suggests a pump problem or circulatory issue.

 

[mogget]

circulatory issue

Let's hope it doesn't need a heart transplant

 

[ToMBoY212]

Right after some tinkering:
took that Thermostat off cylinder and fixed it so it dosn't just spin, now its set at max/80. Turned the dial on the boiler up to 5, then put CH on and all the radiators came on, hot at first but after a while they went to warm, still warm now. However downstairs are all stone cold.

Now I have taken the radiator in the en-suite off a few weeks ago to tile it, this couldn't cause any problems though?

Thanks

 

[ToMBoY212]

Would low pressure cause any issues as I've just noticed my inlet tap wasn't hardly open! So now it's at 3/4 position instead of 1/4

 

[doitall]

What inlet tap

 

[Softus]

JHC. What is this forum coming to?

Even Bamber would have solved this before running to three pages.

 

[doitall]

JHC. What is this forum coming to?

Even Bamber would have solved this before running to three pages.

How very true

 

[weseeyou]

well we are only getting bits of info at a time lol

Its like a murder mystery

What radiator is removed Tomxxxx ? a removed rad could easily cause an air lock/ circulation problem if the pipework hasn't been planned and laid out correctly .Judging by the wiring its a distinct possibility.
What happened when you bled the system ? did all rads have a healthy pressure ?