Worcester boiler heats my water, but not my radiators

[fatboyhouston]

My boiler doesn't want to heat the radiators, but it responds immediately to the hot tap being turned on, and heats the water no problem.

Boiler: Worcester Bosch 28i Junior (approx 3 years old)
Thermostat: Siemens RDJ10RF

This is an intermittent fault which started about a year ago and is becoming more frequent.

I've tried resetting and re-pairing the thermostat controller and receiver; they seem to be communicating fine. There is also an override button on the receiver, which used to turn the heating on right away. Now it doesn't do anything.

I've done a bit of research before posting this. I've read the thermostat and boiler manuals, tried the suggested trouble shooting, and googled around. I've found a few cases with similarities, but I just want to see if anyone can give me a useful hint before I get the pros in.

Many thanks in advance for any advice.

 

[TCCHeating]

Have you tried changing the batteries in the thermostat?

Thoses siemens wireless stats arent known for their reliability. I have replaced many faulty ones myself so I suspect it is this, rather than a boiler problem

 

[fatboyhouston]

Hi, thanks for your reply. I've followed your advice and replaced the batteries (think I've done this in the past too). It hasn't made any difference. The thermostat room unit and receiver seem to be talking to each other fine (when I try to turn up the temperature, the receiver flashes like it wants to turn on the boiler). But nothing happens.

Pressing the override button also doesn't do anything (it used to turn on the heating straight away.

I wonder if there's a missing connection somewhere between my thermostat receiver and the boiler.

Should I try turning my boiler off and on at the mains?

 

[TCCHeating]

I would say the reciever is faulty. Simple check if you have a multimeter and a little electrical knowledge is to check if it is sending a live supply to the boiler. (I suspect it isn't). Otherwise let an engineer have a look. I 'm sure this will probably be the first test he does.

 

[fatboyhouston]

That makes sense. Certainly fits the evidence. I guess it just took a while to go. Heating was on this morning.

Looks like I'm in the market for a new thermostat then. When my boiler was fitted I didn't get a choice, I was just told "This is great, it's exactly what you need".

Any recommendations for thermostats would be very welcome. And in the meantime - is there any way to turn my heating on without using the receiver?

Thanks again for your help, it's much appreciated.

 

[muggles]

Get a Honeywell CM927. Your heating will have to stay off unfortunately, unless you're confident with rewiring your existing stat...

 

[fatboyhouston]

We had a heating engineer round yesterday, and his assessment was that the wireless signal between the receiver and the boiler was being disrupted by our many wireless devices in the house (phones, iPads etc).

I'm a bit surprised by this, as communications between the thermostat room unit and the receiver seem to be fine, and I thought it was a wired connection between the receiver and the boiler (there is a wire going from the receiver to the boiler).

Anyway, he reset the entire system by restarting the thermostat room unit, the receiver, and the boiler, all at the same time. After that our heating came back on, and was controllable via the thermostat. So at least we have heating again. But I'm unconvinced that it's permanently fixed. He recommends a wired thermostat, and I have to admit I've never had problems with those.

Thanks to everyone who contributed advice. If anyone has any thoughts on the above I'd love to hear them.

Cheers.

 

[TCCHeating]

I think he meant the wireless signal between the stat and reciever, rather than the reciever and boiler. As you have correctly stated the reciever is hard wired to the boiler. If The engineer has reset everthing and if it is now working then his job is done! Sounds like it may just have been a communications glitch between the stat and reciever so you'll just have to see how it goes. Good luck

 

[fatboyhouston]

Sadly our problems are not over. As expected, the heating stayed on for a couple of days, then died again. A different engineer came round and recommended we replace the thermostat with a Worcester brand one (also wireless), which can be fitted to the front of the actual boiler.

My concern is that we may pay to have this done, only to experience the same problems again.

I still can't comprehend that if the stat/receiver are faulty there is no way to manually override them and turn on the heating from the boiler. Seems crazy.

 

[C0z1]

we had a similar situation a year ago with a Worcester Bosch Green star boiler and Drayton Wireless Stat. Tried re programming and tried to pair them again. Boiler was supplying hot water, but not heating rads. Turned out tenants had been storing the wireless stat next to computer and all sorts of hi fi equipment, not helped by a wireless computer being in the bedroom below the boiler. We were puzzled by the fact that we couldn't override the stat by manually turning on the heating.
Anyway we eventually replaced the receiver and bought a Honeywell wireless from screwfix, paired successfully and its worked fine ever since. Instructions are cr+p, pairing is fiddly and the stat is nowhere near the quality of the Drayton but it seems to do the job.

 

[jeff the gasman]

The relay has failed in the receiver. When it responds to a demand you should hear an audible click and it should be a strong click.