was it ok before the nest? my experience is that many people (plumbers, electricians and boiler companies) are not well experienced with smart thermostats. rad issues sound like blockages/sludge/balancing. could be worth trying someone else.

My sisters heating went off this week and a plumber said the pressure was too low (after another plumber had previously fixed a rad whose thermostat was stuck) and he fixed the problem and all okay. I would call another plumber (try to get a recommendation) to see if they can help. I’m afraid I know nothing about Nest. What area are you in?

If one radiator is cold on one side and hot on the other side - it has nothing to do with nest but with that radiator or pressure in the boiler. What nest does is sending signal to the boiler when it should go on and heat all connected radiators. If some of the radiator are always cold and others always warm, it might be that nest is only connected to the pipies that serve the warm radiators. Is there any logic to which ones are warm or cold? Are they on different level or same level but different rooms? Where in the house is the termostat located? Overall I think you need a smarter plumber to investigate all potential solutions.Let me know where you are based and maybe I can recommend one specialist.

A Nest thermostat is just a thermostat, albeit a smart one, used to control the boiler. It is unlikely to be the issue.

Have you tried balancing the radiators? We had to do it after we added radiators to the system and that seemed to work

Many thanks all.

The problem with the radiators is unrelated to the nest. Personally I would pay to have the system power flushed (which cleans the inside of radiators and pipes) and then have all the radiators balanced.

The hot water issue might be related to the nest- actually when I had a Nest at the last house my hot water didn’t work and it was because the nest is connected to a valve that controls the water and this had been incorrectly installed.

Thanks Jonathan.

Hello, tgross39! I had the Nest thermostat in my previous house, never met any problems you are talking about.