HR92 - room temperature exceeds settings in 2 areas

[dani]

Hi
I have an evohome with 5 areas. One is floor heating, the other 4 have HR92. In two of them, the radiators get extremely hot, ignoring the set temperature. I have tried binding/unbinding, full reset, changing batteries, nothing works. In the controller, both rooms have "remote sensor" as temperature sensor. I have also ordered, yet to arrive, two DTS92.

Any suggestions how to avoid this waste?

thanks,
Dani

[Richard]

Radiators get hot? What is the actual room temp?

Are the HR's in free air or are they blocked by sofas, beds, etc?

Have a look at this - https://youtu.be/kEAD-IkXRrY

[Archie32]

I also have a multi room setup and I have found if an HR92 is calling for 100% from the boiler relay, for example when a particular schedule for a room is activated, it will cause zones already at a setpoint, possibly having been so for hours, to then start to overshoot.

The degree of overshoot is dependent on how long it takes the new room calling for heat to reach its setpoint (the longer it takes, the higher the overshoot) but also how many other zones are at setpoint with valves partially open. If I have several zones at setpoint and a new zone requiring 100% from the boiler relay, then the overshoot isn't too bad as the DCH flow is shared across the several radiators. If I have just one zone at setpoint and a new zone calling for 100%, then the radiator of the zone at setpoint will quickly rise by as much as 1.5c before the not so smart Evohome will then close the valve and allow that zone to drop back to its setpoint. It's for this reason that I try to schedule zones as close to each other as possible, especially in the morning/evening as this eliminates the overshoot as each zone is calling for 100% at the same time.

Don't get me wrong, Evohome seems very good at maintaining a set temperature but it doesn't seem smart enough to compensate for new zones calling for heat and the impact this may have on zones already at setpoint. I am using Opentherm, which constantly adjusts the DCH flow temperature, so this may also be an additional variable.

[Richard]

I also have a multi room setup and I have found if an HR92 is calling for 100% from the boiler relay, for example when a particular schedule for a room is activated, it will cause zones already at a setpoint, possibly having been so for hours, to then start to overshoot.

The degree of overshoot is dependent on how long it takes the new room calling for heat to reach its setpoint (the longer it takes, the higher the overshoot) but also how many other zones are at setpoint with valves partially open. If I have several zones at setpoint and a new zone requiring 100% from the boiler relay, then the overshoot isn't too bad as the DCH flow is shared across the several radiators. If I have just one zone at setpoint and a new zone calling for 100%, then the radiator of the zone at setpoint will quickly rise by as much as 1.5c before the not so smart Evohome will then close the valve and allow that zone to drop back to its setpoint. It's for this reason that I try to schedule zones as close to each other as possible, especially in the morning/evening as this eliminates the overshoot as each zone is calling for 100% at the same time.

Don't get me wrong, Evohome seems very good at maintaining a set temperature but it doesn't seem smart enough to compensate for new zones calling for heat and the impact this may have on zones already at setpoint. I am using Opentherm, which constantly adjusts the DCH flow temperature, so this may also be an additional variable.

What flow temperature is being called for when the new demand occurs?