CH + DWH circuits controlled separately
Posted: Tue Jan 19, 2021 2:41 pm
Hi,
I have following equipment:
* ATC928G3026 (evotouch) central unit
* BDR91 relay for CH
* ATF500DHW set for DWH (incl. CS92 temperature sensor and BDR91 relay for DWH)
I noticed that the way how my boiler is controlled is different than the common patterns people are discussing on forums (S-Plan, Y-Plan, etc.).
And it caused a problem for me to understand if and how could I configure evohome to control both CH (heating) and DWH (hot water) circuits.
The boiler I am using is Termet Unico Elegance Turbo 24.
The exact model does not matter, the important one is how the boiler is being controlled.
There are basically two dedicated switches directly in the boiler. Switch one is enabling CH heating. Switch two is enabling DWH heating.
The boiler is controlling the priority (DWH over CH).
Boiler also controls 3-port valve which is redirecting hot water either to DWH or to CH circuits.
If both switches are ON (DWH+CH) then it will heat DWH and after that CH.
Please notice that setting ON a selected switch on the boiler is automatically turning the boiler ON (start heating the water) and redirecting the hot water to the appropriate circuit.
So I do not "request hot water" separately from controling DWH/CH valves. It's one switch doing both actions in my case.
Initially I connected one BDR91 relay to CH switch in the boiler.
And the CS92+BDR91 relay to DWH switch in the boiler.
Then I started playing with evotouch configuration software...
And then I learned that some of its assumptions do not really fit to my configuration.
Since I want to control both CH and DWH than I needed to configure both options "Boiler Control" (set to Wireless Relay Box) and "Stored hot water" (set to Enabled).
The effect was that:
1. CH request were OK - turning on my CH's BDR91 relay and enabling CH heating on my boiler
2. DWH request didn't work as expected - it was turning ON not only DWH's BDR91 but also forcing CH's BDR91 Boiler Control ON (requesting the heat water).
This is not what I need since the described behaviour for DWH requests enabled both switched on my boiler (CH and DWH).
And I need DWH only.
Is there a way to achieve the configuration where these two DWH and CH circuits are treated seaprately not influencing each other ?
I found some topics on different forums people having the similar observations and the general recommendation like "turn off Boiler Control completely in evohome configuration".
But this is not what I want - I still want to have a Boiler Control enabled for my CH - setting max. number of cycles per hour for CH etc.
Would it be possible with evohome software ?
If there is some other equipment I need to achieve it I would be happy to consider.
Best regards,
Sebastian
I have following equipment:
* ATC928G3026 (evotouch) central unit
* BDR91 relay for CH
* ATF500DHW set for DWH (incl. CS92 temperature sensor and BDR91 relay for DWH)
I noticed that the way how my boiler is controlled is different than the common patterns people are discussing on forums (S-Plan, Y-Plan, etc.).
And it caused a problem for me to understand if and how could I configure evohome to control both CH (heating) and DWH (hot water) circuits.
The boiler I am using is Termet Unico Elegance Turbo 24.
The exact model does not matter, the important one is how the boiler is being controlled.
There are basically two dedicated switches directly in the boiler. Switch one is enabling CH heating. Switch two is enabling DWH heating.
The boiler is controlling the priority (DWH over CH).
Boiler also controls 3-port valve which is redirecting hot water either to DWH or to CH circuits.
If both switches are ON (DWH+CH) then it will heat DWH and after that CH.
Please notice that setting ON a selected switch on the boiler is automatically turning the boiler ON (start heating the water) and redirecting the hot water to the appropriate circuit.
So I do not "request hot water" separately from controling DWH/CH valves. It's one switch doing both actions in my case.
Initially I connected one BDR91 relay to CH switch in the boiler.
And the CS92+BDR91 relay to DWH switch in the boiler.
Then I started playing with evotouch configuration software...
And then I learned that some of its assumptions do not really fit to my configuration.
Since I want to control both CH and DWH than I needed to configure both options "Boiler Control" (set to Wireless Relay Box) and "Stored hot water" (set to Enabled).
The effect was that:
1. CH request were OK - turning on my CH's BDR91 relay and enabling CH heating on my boiler
2. DWH request didn't work as expected - it was turning ON not only DWH's BDR91 but also forcing CH's BDR91 Boiler Control ON (requesting the heat water).
This is not what I need since the described behaviour for DWH requests enabled both switched on my boiler (CH and DWH).
And I need DWH only.
Is there a way to achieve the configuration where these two DWH and CH circuits are treated seaprately not influencing each other ?
I found some topics on different forums people having the similar observations and the general recommendation like "turn off Boiler Control completely in evohome configuration".
But this is not what I want - I still want to have a Boiler Control enabled for my CH - setting max. number of cycles per hour for CH etc.
Would it be possible with evohome software ?
If there is some other equipment I need to achieve it I would be happy to consider.
Best regards,
Sebastian