Boss Therm (Siemens) BR1 + Boiler. Trouble with CH coming on

[Dennis78A]

Last few days been getting intermittent (seems to be getting worse) problems with getting the CH to kick in. HW seems OK (I think).

BR1 receiver and the BRTRF thermostt.

Had the system for 10+ yrs.

Tried all the usual. Reset, Set, retrain.

All the right lights seem to come on and off etc as I turn the temp up/down on the thermostat. Even reset the BUP2 programmer and got it on manual override at the moment.

But still problems with getting the CH to come on.

The Eco Logic 24+ boiler indicator is in 0 and won't go into C mode to call for heating.

But all of a sudden maybe a few minutes later, or the next morning etc it will work fine.

Could there be something wrong with the boiler before I call out an engineer or is it deffo something to do with the receiver and thermostat which I can buy and rewire myself or local electrician

 

[RandomGrinch]

I would be tempted to link out the receiver, to see if the boiler behaves correctly, ruling out an issue with the stat and receiver.

Moving the wire from L1 to join the wire in LX (with power safely isolated), would link it out - the heating should then turn on/off via the boiler controls.
Can you show us the wiring behind the BR1 cover, so we can confirm?

 

[Dennis78A]

Ok so the grey wire move from L1 to join the black wire in LX to bypass the thermostat?

 

[RandomGrinch]

Ok so the grey wire move from L1 to join the black wire in LX to bypass the thermostat?

Yes, that would do it.

 

[Dennis78A]

Ok, I've linked the two wires together. But still the CH doesn't want to kick in. I've tried everything including setting the programmer to manual on so there's nothing timing wise, thermostat wise that's getting in the way.

The thermostat does seem to still communicate with transmitter though (lights flashing and relay clicking sounds) even with these wires combined. Is that correct?

HW seems to be kicking in when I turn it on after running a load of hot water out of the storage tank.

Could there be something up with the boiler do you think?

 

[RandomGrinch]

Ok, so it sounds like we've ruled out an issue with the thermostat and receiver.
It sounds as if you have a separate programmer and hot water tank?
That would suggest the problem may be with the programmer, or more likely the zone valves.
What programmer do you have?

 

[Dennis78A]

The programmer is BUP2. Yes external programmer (not on the boiler itself) and a hot water tank.

 

[Rodders53]

+1 on a CH zone valve issue

Is the manual lever stiff or floppy when the Thermostat is 'calling' for heat.

 

[Dennis78A]

well the boiler is on O when there is a call for heat. It's not kicking in. The zone valve lever seems stiff but I can manually move it across without too much force if that's what's you're asking.

But what I've noticed is the the casing on that zone valve as opposed to the other one which I presume is for the HW is slightly loose and raised up. They are both relatively new, well a few years old as the hot water tank and everything from the piping to things like valves was replaced in 2019/20 I think.

 

[Rodders53]

Pics of the valves may help?

With both HW and CH stat's satisfied, compare the two levers' stiffness...
Then with HW calling does the HW lever become very floppy cf the CH one?

Manually operate the CH lever hard and fast against the spring... you might hear a microswitch click at the end and then again as the lever returns ??? Does the boiler do anything then (briefly)??

Do the valve bodies heat up when on due to the electric motor inside opening the valve? Or is the CH one cold? Do you hear either of the motors operating when a call for heat is present or removed when you are near them?

Do you have a multimeter and do you know how to use one, safely, on potentially live mains electrical connections?

 

[CountryFan]

What brand of valve? Sounds like a Drayton loose motor housing - had this a couple of times

 

[RandomGrinch]

But what I've noticed is the the casing on that zone valve as opposed to the other one which I presume is for the HW is slightly loose and raised up.

Have you tried to see if it will resit properly?

As @Rodders53 posts, it's most likely the valves.

For a quick check, you could also bridge out the programmer, i.e. connect terminal 4 directly to L (a pic of the wiring behind the programmer will confirm).
If the problem is still there, it more or less confirms the zone valve/actuator is at fault.

 

[Dennis78A]

Update. It works now when I turned the hot water on. The radiators have got quite hot.

Confused!

 

[Mister Banks]

Have you manually opened the CH zone valve? If so that is why you now get CH heat when the HW demands it.

 

[CountryFan]

Update. It works now when I turned the hot water on. The radiators have got quite hot.

Confused!

Sounds possibly more like a 3 port mid position valve then. As per @Rodders53 post a photo of the valve