Biasi M90e 28s external thermostat wiring

[the_jinj]

Hi

I recently got a Hortsmann HRFS1 thermostat to control my Biasi boiler.
The Hortsmann is setup ok and appears to be switching on and off as desired. 2 core running to boiler from OM and NO contacts of the thermostat to the boiler.
According to the manual you connect to connector 1 and 3 (with link removed). I notice that there is a link from the supply neutral to connector 1 on the no voltage connector - is this correct or has it been added at some point? Connector 2 is grey, 3 red.

I've attached a pic of the boiler side wiring. The service manual doesn't show the connections from the connector to pcb so not sure.

Untitled

• the_jinj
• 13 Mar 2014
• 1

Any help appreciated.

Cheers

 

[D_Hailsham]

The red, grey and blue wires are the boiler side of the connector. Your stat will connect to 1 and 3 on the other side of the connector.

The stat is just a temperature controlled switch. If there was no wire connected to 3 on the boiler side, the boiler would never light.

 

[the_jinj]

The red, grey and blue wires are the boiler side of the connector. Your stat will connect to 1 and 3 on the other side of the connector.

The stat is just a temperature controlled switch. If there was no wire connected to 3 on the boiler side, the boiler would never light.

I had to set the internal timer to override. Was thinking about the voltless contacts in the wrong way, silly me. Now sorted

 

[jm66666]

Hi

Trying to connect a hive thermostat to same wiring how dis you get it to work please.

Any help appreciated
Cheers

 

[CountryFan]

Hi

Trying to connect a hive thermostat to same wiring how dis you get it to work please.

Any help appreciated
Cheers

Did they not answer the question in the last post about the timer? Also, you’ve hijacked an 11 year old thread. It would have been better to start your own.

 

[jm66666]

First time here, first time asking for help.

Plus only post I've seen with the same wiring so felt had to jump on.
Cheers for being super helpful