Help: Baxi EcoBlue 24 keeps heating water

OU812

Have a Baxi EcoBlue 24. Coming up on two and a half years old. It's controlled by a Nest thermostat which is currently set to off (for the summer).

Due to the weird way the house is plumbed, three of the four upstairs radiators heat up when the water is being heated.

We can have the water on without the heat, but not the heat without the water - was like that when we bought the house.

For some reason, every evening, the boiler starts heating water which heats the upstairs of the house also.

Is there any way of stopping this apart from turning the boiler off?

K.Flyer

You would be better getting someone who knows and understands heating systems and controls out to examine and diagnose the problem.
It may be a problematic zone valve, a thermostat control or an issue with the timed device.

jimf

does the nest have some kind of built in feature for hot water safety re legionnaires /legionella


maybe me talking out my rear orifice as usual

seem to remember reading something about a safety feature that needs disabling

OU812

jimf wrote: »

does the nest have some kind of built in feature for hot water safety re legionnaires /legionella


maybe me talking out my rear orifice as usual

seem to remember reading something about a safety feature that needs disabling

Not that I’m aware of.

Phileas Frog

OU812 wrote: »

Not that I’m aware of.

It does ...

https://support.google.com/googlenest/answer/9256656?hl=en

OU812

Phileas Frog wrote: »

It does ...

https://support.google.com/googlenest/answer/9256656?hl=en

Hmmm... thanks for that.

The nest app shows no activity at all & appears off when the water is heating. Which is confusing.

Wearb

From PS' link above: "Bacteria Prevention mode will activate if your domestic water hasn’t been heated for at least 2 consecutive hours in the last 48 hours" That seem like a huge waste to me. e.g. Suppose that you have the hot-water on for 1 hour each day (more than enough for some), this doesn't go near satisfying the nest requirements of 2 consecutive hours. In that scenario the nest would kick in every 2 days, regardless of the water having been heated daily for an hour. Seems that in that scenario it would be as well to turn off the hot-water and let the Bacteria Prevention mechanism heat the water.

I am sure that the procedure is scientifically sound, but well out of step with the actual risk. My attic tank would be between those risk temperatures every summer as would thousands of others.

I am not advocating bypassing such safety features though as that would be far beyond my pay grade.

jimf

Wearb wrote: »

From PS' link above: "Bacteria Prevention mode will activate if your domestic water hasn’t been heated for at least 2 consecutive hours in the last 48 hours" That seem like a huge waste to me. e.g. Suppose that you have the hot-water on for 1 hour each day (more than enough for some), this doesn't go near satisfying the nest requirements of 2 consecutive hours. In that scenario the nest would kick in every 2 days, regardless of the water having been heated daily for an hour. Seems that in that scenario it would be as well to turn off the hot-water and let the Bacteria Prevention mechanism heat the water.

I am sure that the procedure is scientifically sound, but well out of step with the actual risk. My attic tank would be between those risk temperatures every summer as would thousands of others.

I am not advocating bypassing such safety features though as that would be far beyond my pay grade.

agree 100% about safety feature bypassing or disabling wearb

bit like us doing that with a hl stat on a boiler

if the manf didn't think twas needed why have it as a feature in the first place


it was something I read a while back possibly even here on boards

Traditionally setting the boiler thermostat to 65c and the cylinder stat to 60c was all that was required for safe hot water usage but now with funky controls with pretty lights the manufacturers are finding themselves having to creating a balance with overall lower temperatures for efficiency but still maintaining safe hot water usage which would still requires a higher cylinder temperature at given times.