Automatic bypass query

[colin_]

Hi

I have an automatic bypass valve (ABV) fitted on my system but I am having some issues understanding how it does its job when the TRVs are restricted by the Evohome control system

Lets say it is set at 0.4 and the TRVs are nearly closed (say they are 0.35), when the boiler fires I presume that the ABV will cut in.

Does it come in fully and shunt all the heat through it (simply on/off) and so none gets to the radiators or does it simply take 0.05 of it (variable) and the 0.35 flows through the TRVs as they need, so they can heat up.

What is a normal setting for it (initially the heating company set it at 0.15 but when the Evohome came on with restricted valve positions all that happened is that the ABV got hot and the radiators remained cold), they have now just set it at 0.5.

Thanks
Colin

 

[colin_]

There’s obviously a problem somewhere, as if the rooms aren’t at the set point the Evohome should be calling for heat longer than 1 minute. I’d suggest doing a full system reset and setting up from the start again.

Hi

It is one room that is acting awkward with respect to the set point. The rest say they are at temperature on the controller but the data says they are calling for heat but not getting warm (as the boiler needs a good 5 minutes to raise its temperature by just 1-3 degrees ( 2 minutes gives only gives around 1-2 degrees more).

I am gathering information for the installers and will ask if they should set it up again (but suspect will still have some issue with the boiler output)

Thanks
Colin

 

[EvilDrPorkChop]

Hi

It is one room that is acting awkward with respect to the set point. The rest say they are at temperature on the controller but the data says they are calling for heat but not getting warm (as the boiler needs a good 5 minutes to raise its temperature by just 1-3 degrees ( 2 minutes gives only gives arounf 1-2 degrees more).

I am gathering information for the installers and will ask if they should set it up again (but suspect willstill have some issue with the boiler output)

Thanks
Colin

Out of interest have you got the weather compensation features and load compensation turned on under the settings? That maybe your issue too. Especially if it’s been set incorrectly.

 

[colin_]

Out of interest have you got the weather compensation features and load compensation turned on under the settings? That maybe your issue too. Especially if it’s been set incorrectly.

Hi

These functions are not set (say disabled)

I have set the min on time to 2 minutes as per previous suggestion to see if that makes a difference but so far not (temperature still not going up by more than a few degrees from the boiler) but will monitor it today (as I am working directly above the boiler I can hear when it comes on)

Thanks
Colin