Install the app
How to install the app on iOS

Follow along with the video below to see how to install our site as a web app on your home screen.

Note: This feature may not be available in some browsers.

Welcome to the forum. Although you can post in any forum, the USA forum is here in case of local regs or laws

Feb 10, 2019
2
1
3
Member Type
DIY or Homeowner
Hi

I’ve got Valliant combi boiler converted to system. Downstairs I have underfloor heating with Heatmiser thermostats and upstairs I use Nest (which also seems to be controlling hot water). The problem is that upstairs heating will only work if one of the zones downstairs is calling for heat. Unfortunately the two controllers were installed by two contractors during house renovation so now I have to try to figure it out if this issue can be resolved at all.

Btw, I’m a home owner, not plumber or gas engineer.

Is anyone here able to offer advise please?

Thank you in advance!
Ilija
 
now I have to try to figure it out if this issue can be resolved at all.

A competent heating engineer will be able to sort the problem out for you. Probably best to check that they are familiar with Nest before booking but most are these days. I would expect it to be trivial to get the upstairs zone to provide the boiler with a demand signal.

What will be harder is to make sure that the zones are synchronised appropriately so that the boiler doesn't 'short cycle'. There are several possible approaches to this task, each with their pros and cons, so you need someone with appropriate experience to advise you.

For this sort of thing, I suggest you get a small local independent heating-engineer who has been in the business for a good number of years and has been recommended by someone you know.
 

Official Sponsors of Plumbers Talk

Similar plumbing topics

A
Replies
2
Views
1K
Boiler Advice Forum
Deleted member 120897
D

We recommend City Plumbing Supplies, BES, and Plumbing Superstore for all plumbing supplies.