Hive and Ideal Logic Combi 30

[flameport]

The old receiver uses Opentherm. A Hive receiver does not.

With the mains power to the boiler switched off:
Disconnect the old receiver wires, and either link the two Opentherm +- wires together, or buy the link plug which does the same thing.
The Hive receiver connects to LNE for power, and the other two switched connections go where the red link is in the 'thermostat' terminals as in the original photo.

Buying another opentherm receiver might save you 1% on your gas bill assuming it works properly with your boiler, which it probably won't.
All the rest about TRVs is unrelated and irrelevant.

 

[Taylortwocities]

Nest and Hive connect to your boiler in the same way.
You’ll need to link out the PRT3 if you do anything.

 

[Gooner23]

Nest and Hive connect to your boiler in the same way.
You’ll need to link out the PRT3 if you do anything.[/ok
looks like im buggered then lol

 

[Taylortwocities]

Not really, just get a link plug and install the Hive.

Meerkat

• Taylortwocities
• 11 Dec 2009
• 53

Simples!

 

[Gooner23]

Got this coming tomorrow, hope it works

 

[ericmark]

Nest and Hive connect to your boiler in the same way.
You’ll need to link out the PRT3 if you do anything.

No they do not, Hive is on/off only, Nest is either on/off or OpenTherm it has both options.

Buying another opentherm receiver might save you 1% on your gas bill assuming it works properly with your boiler, which it probably won't.
All the rest about TRVs is unrelated and irrelevant.

May be your right, I really don't know how one would measure? The theory is every time a boiler switches off, any heat in the boiler is lost through the flue, and the harder the boiler is working, the hotter it is, so the more heat is lost, so having a boiler running at 7 kW for 18 hours is claimed to use less energy than the same boiler running for 10 on/off runs of 27 minutes at 28 kW. Also the hysteresis in the temperature is also reduced, so home is more comfortable.

What would matter is at what burn rate the boiler is most efficient, if more efficient at 28 kW output to 7 kW output all the gains could be lost, and with the reverse if at 28 kW it does not gain latent heat and at 7 kW it does, then the difference would be increased. And there could be large gains running at 7 kW.

What is clear is any thermostat using a mark/space ratio to stop over shooting and improve the hysteresis would result in more fuel being used.

The same arguments are true with geofencing, I have tried using geofencing however it has resulted in a temperature over shoot in this house, and with mothers it did not get to target temperature in time. And turning off heating the home does not cool that fast, so likely very little saving.

With an annual fuel bill for heating of around £500, working on a 10 year before some thing needs changing or repairing so looking at pay back in 10 years, in real terms the money saving units need to cost £500 or less if they save 10%. So it seems unlikely that all these clever systems really save money.

So only real benefit is comfort, and it does seem likely analogue control with OpenTherm is likely to give a more constant temperature to an on/off control, so using the PRT3 will be better than using Hive as a simple single thermostat, where Hive gains is when you also use linked TRV heads.

 

[stem]

There is a guy called @stem who is likely the best on here to advise how to get around that missing link wire plug, I would hold off until he replies.

Sorry, I can't add anything to what has already been said.