Preheat when no heating is scheduled

[karlic]

My Nest controls a Baxi 200 heat only boiler that is under 18 months old, which feeds a Megaflo system.

It is summer time and the boiler never comes on for heating. We have a daily hot water schedule from 2pm to 4pm. However, the boiler is regularly firing up for a minute or two and I cannot find a setting to stop this. I tried True Radiant, but that is only for heating.

During the night this is costing us around 60p in gas when nothing is scheduled and I can't calculate the daytime cost. With prices rising even further it would be great if anyone has some ideas.

[CoolingWizard]

This is not a problem with your Nest Thermostat.  This is a feature of your boiler system. It keeps the water hot by cycling on and circulating the water. 

[karlic]

Thanks for the information. The Baxi serves hot water and heating. So it sounds like you are saying it is not possible to stop this behaviour, apart from manually turning off the boiler?

[CoolingWizard]

Unfortunately you cannot stop that feature. Your cannot be turned off to save money. 

[karlic]

After speaking with Baxi technical support, they say this is not possible with this boiler. It has to receive an instruction and this is either a control issue from Nest, or it can be a faulty valve.

They also said it does the boiler no harm to turn it off at night until we resolve the issue.

[Jeff]

Hi karlic,

It looks like CoolingWizard and you were able to find an answer to the issue here, but I wanted to check in to see if there was anything else you might need. If there's anything I can do for you, just let me know.

Thanks,

Jeff

[karlic]

Thanks Jeff.

We never found a solution between plumbers and Baxi. The boiler still fires up for a minute or two whenever it fancies and this is not a combiner's boiler that needs to pre-heat; we have a Megaflow system.

The current solution to save a fortune is just turning off the boiler to 22 hours a day manually and setting an alarm on my phone to remind us to turn it back on. I only have it on when it is programmed to heat water, which makes a complete mockery of having Nest in the first place.

Cheers,

Karl