Cylinder Stat Compatible With Nest System

Toots

I'm hoping someone could help me here - I'm trying to figure out what cylinder stat sensor & receiver I need to get. Basically at the minute we have an oil central heating system that isn't zoned - if we want to heat the hot water we have to either switch on the immersion or turn the heating on; we don't have the option to heat the water only. We have a Nest thermostat which we use to turn on and off the heating, this has a hot water only function as well, but we can't use that at the minute because our heating system won't do hot water only.

The oil boiler is located outside the house, and the Nest Heat Link is on the wall beside the back door in the utility room. The thermostat is located in the hall and our hot water cylinder is in the hotpress. When we had the heating company out to do up the quote for the job, they mentioned that the sensor/receiver they'd usually use to monitor when the hot water in the cylinder reaches the desired temperature wouldn't work with our Nest and that we'd need to source a compatible one ourselves.

Does anyone know of a sensor/receiver that would work with the Nest system? Or if there's some sort of workaround that would allow us to control our hot water and heating from the Nest? Many thanks.

10-10-20

So do you have a valve now fitted to turn on and off the flow to the cylinder, and if so how is it currently controlled?

Toots

As far as I know it's a mechanised valve that opens when our boiler fires. The boiler is controlled by the nest heat link.

rightjob!

a standard hot water cylinder thermostat is what you use,you wont be able to check the temperature of the water.

The stat would be set at 65 and you dont adjust it

Toots

But with the standard thermometer, how will it "talk" to my nest to tell it when the water has reached 65 and to turn off the boiler?

Toots

Not sure if this helps but on the quotes it has a list of all the work to be done and the bit that mentions a sensor says:

"To zone heating system properly into radiators and hot water zones.

(Customer needs to supply sensor and receiver to connect to existing time

clock)"

Wearb

As above, you first need to have your system zoned, ie have a motorized valve (2) for each of the zones. These zone valves will have to be wired so that they call on the boiler. The nest will call on the valves, then valves on the boiler.

From your OP, your heatlink (and Nest stat) has the facility to operate heating and hot-water separately. If so then you wont need sensor and receiver mentioned above.

Toots

Grand so. I know the engineer mentioned if we want to avail of the SEAI grant for heating controls we'd need to have a sensor because the SEAI want to see the heating/hot water controlled by temperature and time.

Wearb

You can use the existing cylinder stat to control the cylinder temperature and the nest used to turn it on and off AFAIK. I am more familiar with Hive, but I think they're the same in that regard.

Toots

We're wondering should we have gone with the hive instead 🤣 the Nest looks lovely but it's a bit finnickey - the learning function seems to think we want the heat on all the time.

Wearb

https://www.boards.ie/discussion/comment/118582293#Comment_118582293

I dislike the extra smart features that they have. They are a nightmare for the non technically minded. I fitted a heat only one a long time ago for someone and I kept getting call backs for things that seemed like a fault, but was only the features of the nest working as designed.

Bit of extra info below on the nest.

https://support.google.com/googlenest/answer/9209007?hl=en

Toots

I'm really not sure mine is working right because I've disabled the auto learning several times but it keeps kicking back on. My husband and I would both be quite techy but I'm struggling with the nest. I only chose it over the Hive because our cameras and smoke alarms are all the nest ones and I figured it would be handier to have them all run off one app.

Wearb

I've disabled the auto learning several times but it keeps kicking back on.

That's typical of the problems that I hear about with them. Perhaps try to get in touch with Nest support (Google). There has to be a fix for that problem. If you do sort it out, perhaps you could post solution here please?

BTW it said auto schedule on the link above, but perhaps that's the same as auto learning.

Toots

Yeah I think they seem to use auto schedule/learning interchangeably. I'll have to try and get in touch with Support. I'll definitely post back here with any solution they offer (and whether or not it works!)