Nest 3rd Gen thermostat compatible with existing frost protection thermostat

[Dave-1976]

Hello, hope you are well.

I can't seem to find the answer to my query before I buy a Nest, and wondered if an expert could confirm please.

I have a Y plan system which consists of:-

- Boiler in my garage which has a Drayton frost protection thermostat next to it which is wired to a pipe thermostat (I think that's what its called) fixed to the water pipes that comes out the boiler. There is a fused switch and junction box next to the Drayton thermostat.

- A thick white wire comes from the junction box and runs into the roof space and appears into the airing cupboard on the landing.

- A Hot water cylinder is in the cupboard along with the pump and cylinder thermostat.

- All wires go into a big Honeywell junction box from all components which consist of Honeywell programmer, Honeywell wireless thermostat receiver. The wireless thermostat is downstairs near a radiator in the hall with locked valves.


So I know the Nest has safety frost protection, but assuming that its only going to protect the pipes and boiler if they were internal.

Will I need two Nest thermostats or will the existing Frost protection thermostat work interdependently regardless of the Nest which would mean I only need to get one.

I don't need to know any installation info as I will be looking to find a local installer.

Thanks in advance for the advice.

Dave

 

[flameport]

Yes, the existing frost thermostat will continue to work, no modifications or extra Nest required.

 

[Dave-1976]

Hi flameport, thanks for the prompt reply. This is great news and will order the nest installation today.

Cheers

Dave

 

[dilalio]

Hi flameport, thanks for the prompt reply. This is great news and will order the nest installation today.

Cheers

Dave

You could go through the Nest Pro network and upon submission of your order, notify that your boiler is in the garage and existing separate frost protection needs to be maintained... Heads up for the installer and all that

 

[Dave-1976]

Hi Dilalio, hope you are well.

I got some good discount the B&Q so picked one up on Saturday and have the company who we use to do our Boiler service coming out to set it up.

Thanks

Dave

 

[Pilkey]

Hi guys - a question that @flameport might know the answer to judging by the above. Apologies if this is duplicating Dave's question (hopefully not) but want to be 100% certain before I splash out on Nest!

I have a very old gas system boiler connected to a frost stat in the loft, which is not insulated (old house!). The system set-up is as follows:

- Gas system boiler and programmer in kitchen
- Thermostat in living room
- Mega-flo hot water tank + pump in loft
- Honeywell frost-stat attached to piping in the loft (set to 3C)

The question: if I get Nest 3rd generation thermostat installed, will the frost stat still work as normal and turn on the heating to protect the pipes in the loft? I'm not sure how Nest will 'talk to' the frost stat or vice versa...will the frost stat simply override Nest when the temperature in loft reaches 3C?

Really appreciate your input!
Pilkey

 

[flameport]

The Nest replaces the programmer, living room thermostat removed and the 2 switch wires connected together, frost thermostat will work exactly as it does now.

I'm not sure how Nest will 'talk to' the frost stat or vice versa

It doesn't - the old programmer, the thermostat and the Nest are just on/off switches.

You need to get some loft insulation - you are throwing money away without it.