Boiler not turning off now won’t turn on without HW

[Bmd33]

Hello

The other day my boiler suddenly stopped turning off either with the thermostat or the control box, it wouldn’t switch on the hot water either. I had someone to check the boiler (under warranty) and they said it isn’t the boiler but somewhere else in the system.

Having read a few threads on here I suspected the 3 point valve so had a look. I took it off with the push button and the spindle underneath moves easily but a tiny amount, I can’t imagine it can get to the three positions but could be wrong. The photos trying to show how far it moves. The levers on it do move when the boiler is switched on and off.

I put it back and everything seemed to start working again but now the heating won’t turn on unless the hot water is heating up (which it obviously does then turns off so it’s freezing!). Not sure why it’s changed from one problem to another, can anyone advise? I would much rather have the heating on and can’t get it changed until the middle of next week by someone that knows what they’re doing unlike me! Does it sound like this part is the issue?

I’ve got a Baxi 600 with a tank and cylinder set up

 

[terryplumb]

Show us a picture of the thermostat on the cylinder.

 

[Bmd33]

Any use? It’s so dark in there!

 

[terryplumb]

If you want heating on ,release that thermostat off the cylinder. Set programmer to domestic hot water,and manually latch the 3 port valve open.
You may need to lower the boilers stat so cylinder water doesn't get excessively hot.

 

[Bmd33]

If you want heating on ,release that thermostat off the cylinder. Set programmer to domestic hot water,and manually latch the 3 port valve open.
You may need to lower the boilers stat so cylinder water doesn't get excessively hot.

Thank you, how do I take it off the cylinder? I’ve been trying to work out how to open the valve but can’t seem to move any of the levers myself?

 

[terryplumb]

The stat sits in a "nest" ,(for want of a better description) cut out of the insulation. The banding keeps it pressed inward against the copper cylinder.
To latch the motorised valve open use the lever on outside of body ,slide it and lock it in place .

 

[Bmd33]

Thank you I still can’t move the lever unfortunately, it’s stuck over to the right in this photo but obviously I’m looking at it upside down iyswim

 

[terryplumb]

Take the whole actuator head off the brass body (and leave it off) ,like you did earlier,and use your pliers to turn the spindle to open flow to radiators.
Bit of a bodge ,but will give you heat.

 

[Bmd33]

Take the whole actuator head off the brass body (and leave it off) ,like you did earlier,and use your pliers to turn the spindle to open flow to radiators.
Bit of a bodge ,but will give you heat.

Thank you, I’ll give it a go tomorrow

 

[Bmd33]

Take the whole actuator head off the brass body (and leave it off) ,like you did earlier,and use your pliers to turn the spindle to open flow to radiators.
Bit of a bodge ,but will give you heat.

Just tried but I don’t know which way I’m meant to turn it? I want the water off don’t I so it doesn’t cut off the boiler?

 

[terryplumb]

Sorry,not with you ? If you refer to the spindle in the valve body putting it in mid position will heat both cylinder and radiators.

 

[Bmd33]

Sorry,not with you ? If you refer to the spindle in the valve body putting it in mid position will heat both cylinder and radiators.

Don’t I want it only going to the radiators so the water doesn’t reach temperature and turn it off?

 

[terryplumb]

Have you removed the thermostat from the hot water cylinder ? Its that which would turn off the boiler when cylinder is heated. If it's not on the cylinder it will never be satisfied and boiler will continuously run.
If you only want the radiators to heat just position the spindle in the valve body accordingly.

 

[Bmd33]

Have you removed the thermostat from the hot water cylinder ? Its that which would turn off the boiler when cylinder is heated. If it's not on the cylinder it will never be satisfied and boiler will continuously run.
If you only want the radiators to heat just position the spindle in the valve body accordingly.

Which way does the spindle needs to be turned, towards the heat pipe or towards the cylinder?

 

[livingstoned]

Those spindles do only turn about 20°. Like less than 10 minutes on a clock face.
Assuming what's wrong is that the motorised valve has stopped working (you may be able to replace the motor inside, in due course)
With the side lever on the motorised valve head you can latch (against the spring) it in the M position which means manual - it'll then be open to heating AND HW,
If you turn the cylinder thermostat right up, to 90 sort of thing, the boiler will come on as long as your programmer is calling for HW.
The temperature actually on the boiler, set lowish, will give you some HW and at a reasonable temperature, and heat in the rads, at the same time.

The CH setting on the programmer will do nothing, because the valve isn't moving.

If you have the head off the valve, leave the spindle in the middle,. The outlet from the 3 port valve marked "B" is the one to HW. You would turn the spindle away from it, to make the rubber ball inside bung up the CH outlet and let water go to HW. BUt you need both I expect.

Do you have an electric immersion heater on the cylinder.?