Honeywell Thermostat Help Please

[ruggief]

Hi I have just moved house and can't make sense of the system. Before I go to the expense of an engineer fallout on a weekend thought I'd try here.

I have a wireless relay in the hall and a thermostat. All radiators bar one have tvrs set to 4 or 5. Boiler is working firing on but radiators won't turn on. I've whacked thermostat right up over 20 as it's currently showing 13.5 degrees (yes I'm cold) but nothing will work. I've tried repairing and rebinding devices per troubleshooting tips and they are paired.

Any advice please?

[The Builder]

Good point bhg.
It could be the cylinder stat (if there is one).

I still can't figure out why the "heat leak" rad is heating up on its own though.

[Ryzen]

If the pumps running then it will be the diverter valve..this is generally a silver box by your pump.

[Ryzen]

If the cylinder stat is still demanding ...on DHW priority..the circ to the CH pipes should remain unheated.

[bhg481]

I'm also puzzled by the non-TRV radiator getting warm; do you mean warm or hot?

[The Builder]

Ryzen ...

If the DV is stuck on "Hot Water", I just wonder how any flow is getting to the heat leak rad?

[The Builder]

Ruggi ..........

I hope you realise that there are some big guns on your case here....... and I don't mean me... ;o)

[Atheist]

ruggief; have you tried bleeding radiators to see if there is water in them? Are any of them warm at the bottom and cold at the top?

[Ryzen]

Fair point TB.....I recon the non TRV rad is connected to the DHW circ to enable towel drying in the summer when the CH is off.

[bhg481]

Ryzen - that would be a silly design as once the diverter had switched to radiator flow the heat-sink radiator would be out of the system.

[bhg481]

Is there a chance that the boiler thermostat was turned down for the summer so needs to be turned up?

[bhg481]

The pipe on the inlet side of the pump should be too hot to keep your hand on. Is it?
After leaving the pump the flow goes to the diverter valve; by feeling the two outlet pipes you can tell which way the water is flowing by its temperature. If the flow is towards the cylinder manually operate the diverter valve. You should then feel the pipe to the radiators getting hot, so go and feel the radiators.

[Ryzen]

The system may be gravity DHW and pumped CH with a zone valve on the DHW...the pump may be running slow and the non TRV is on the DHW before the valve i.e gravity fed.

[ruggief]

Sorry I meant I watched the tube videos as suggested and the pump is doing what it should be so it's not that. I have only one thermostat and it's a wireless one Honeywell DT92E. I've done all the troubleshooting steps and according to them everything is working but it isn't as I have no heating.

[Ryzen]

Ruggi ..have you found your diverter valve?

[davebro]

Call an engineer, put another jumper on and have a cup of Bovril!

[Ryzen]

...and get ya wallet out :-)

[bhg481]

Ryzen - the non-TRV radiator has to be on the same side of the diverter valve as all the other radiators otherwise, when the water is flowing to the radiators and all the TRVs have turned off their radiators, the pump is operating against a closed system.
Ruggi - the boiler must have a temperature control on it; so must the hot water cylinder. If there is no thermostat on the cylinder there is no means for the system to operate the diverter valve.

[The Builder]

Yep, nothing else for it. unfortunately, none of this makes any sense.

I would love to get feedback when you do get the answer.

[ruggief]

Thank you all, you are all amazing. No I can't locate a divertor valve. I really wish I could attach a photo. Yes I've bled them all and no water. Non tvr is warm not hot. Pipe is too hot to touch.

[Ryzen]

I agree bhg....we have both seen some wonderful designs i'm sure.Still no mention from Ruggi ref a DV..worrying?