nest installation

hargo

My daughter just had a third generation nest installed on her gas boiler. Prior to the installation she could turn the thermostat on the wall to zero and heat hot water only. There is a motorised valve on the system. Since the nest was installed she has to turn off all the radiators to have hot water only. This doesn't seem right to me. Does anyone have any experience of this?

serox_21

I assume the nest thermostat was not installed correctly.
Call back the installer to fix it. It should work independently for hot water and heating.

hargo

The reason i made the enquiry was i am not sure what way the system should work but i feel it is installed as you say incorrectly.
Her nest was installed by Electric Ireland. The guy who installed it disconnected her circulating pump. When she complained her boiler was cutting out a second man came out checked the nest voltage and said her boiler was the problem and it was coincidence that the boiler was broken! She then paid a gas engineer to look at her boiler who told her that her circulating pump had been disconnected from the live when the nest was installed. It took 3 weeks to finally get another man back who wired the circulating pump back.
His attitude when asked about the hot water operating separately was I didn't do the initial install and if you turn off every radiator separately you get hot water.
Thought their might be a plumber out there who could advise how this system should work as clearly Electric Ireland don't.
.

whizbang

I think you should get your money back asap.
As you say, clearly they don't know how the system should work.

Unfortunately the nest can only control one device at once i.e. in your case > boiler.
If you want separate hot water, then a second nest is required.

Outkast_IRE

hargo wrote: »

My daughter just had a third generation nest installed on her gas boiler. Prior to the installation she could turn the thermostat on the wall to zero and heat hot water only. There is a motorised valve on the system. Since the nest was installed she has to turn off all the radiators to have hot water only. This doesn't seem right to me. Does anyone have any experience of this?

First things first .
No.1 you need to confirm the plumbing is correct for 2 zones. Hot water and heating this would generally require 2 zone valves , usually located in the hot press . What I find odd is how she needed to turn the wall stat to 0 on the heating to get hot water only ,

Generally in. 2 zone system the controller on the wall has 2 zones each independently capable of running without needing to fiddle with stats.

I would be concerned that there is only one zone valve. Or maybe there is a chance it's a y type system.

If the wet side of the system is wrong then the nest install is never going to meet your requirements..

The third gen nest is capable of doing hot water and heating but only if the system plumbing is correct .

hargo

Outkast Ire , the third man who came did mention something about Y system but I don't know what that is.
My understanding of her system was open vented with one motorised valve at the water tank. There was no seperate way at the timer clock for the boiler of turning on hot water only but she could turn the wall thermostat to zero and have hot water only. This thermostat appears to be disconnected now and the way to have hot water only now is by turning off every radiator which seems a backward step.
The nest appears to be set up so that it controls only the boiler starting or stoping during a specified time to keep a specified home temperature and that the valve at the tank is always open. I would have thought that it was still possible to control this valve with the old thermostat switch to have hot water only rather than turn off every radiator. Would hot water be running through all the pipes in the house with this set up rather than just just the tank coil?