Issue with UFH and EvoHome

[ALEXJ21]

Hello,

Hello,

Yesterday a technician came and installed a Honeywell evohome setup on my house. For first floor, since I didn't want to control the temp over zones and I wanted over the entire floor, he used a BDR91 RF connected to a grundfos pump and configured as a zone valve in the evohome and the evohome central acts as a thermostat for the BDR91 RF.
For the 2nd floor he used HCC80 and actuators + temperature sensors in the zones that I want to control and each one was binded to a zone and to a actuator.

All good, it switches correctly when there is a request for heat, it stops etc so it looks like this part is done ok. For first floor as well, as soon as the first floor requests heating, it starts up the pump and the combi gas boiler Ariston HS Premium 30KW. The problem is that it never reaches the temperature that I've set because appearently the boiler(didn't notice yesterday night if it was the same) is up and running but it is heating for some seconds, then stops heating for a few minutes and so on.

Basically it stays like this for a few minutes: https://imgur.com/a/iiG5b7z
Then it starts heating for ~10 seconds: https://imgur.com/a/yfgHnVy

Wiring of BDR91 against the grundfos pump: https://imgur.com/a/ycnTW7x / https://imgur.com/a/cQRCKQC
First Floor with BDR91 and pump: https://imgur.com/a/SUxoPfZ

So basically the combi gas boiler goes like this continuously, doesn't matter if the request for heat comes only from first floor for the entire floor with the valve, or from 2nd floor from a zone, or from both floors at the same time.

Pressure is fine, 1.5 BAR

Debitmeters are as well ok, each circuit has 2-3L/min.

I'm losing my mind - uninstalled as well the thermostat and still nothing. Reinstalled and added only first floor - nothing. Reset combi gas - nothing. Changed the pressure, 0.5 to 1.5 and nothing.

For me it looks like it's some strange loop and I don't know but I think it is related to the thing from below, either the wiring is incorrect for this or I don't know. Called Ariston, they said that it is a circulating issue if the Ariston Combi Gas behaves like this and they say it's not due to the boiler, but they will come in the next 2 days to check. The technician that installed the EvoHome automation says the boiler is the issue, but this started happening once evohome was installed. Before this, the boiler ran without a thermostat, simple on/off with fixed temperature.

Thank you in advance

[Richard]

Looks a very rough installation for a technician? BDR91 at the boiler is not in the best location either?

If you just have UFH maybe set the boiler to a lower flow temperature and get rid of the thermostat on the UFH manifold?

Have you just tried the setup with just evotouch controller and BDR91 as zone valve zone and boiler BDR91 setup as appliance relay first before adding HCC UFH controller?