Red LED flashing on mystery box in airing cupboard

[Newboy]

Is there nobody to check on the property?

Given the current 'cold snap' I'd be inclined to get it checked sooner rather than later - and shut off the mains water supply!

Just the thermostat model number - easy to pair to the relay if you follow the instructions.

 

[stem]

It's a Honeywell BDR91 Relay Module. I have attached the instructions below.

 

[floehopper]

It's a Honeywell BDR91 Relay Module. I have attached the instructions below.

Thanks for the positive identification.

 

[floehopper]

I can't find the thermostat anywhere, despite the tenants suggesting where they left it. Can I replace just the thermostat and pair it with the existing relay unit, or do I have to replace both?

The radiators warm up when I press the override button on the (separate) timer controller. Given that the red LED is still flashing on the relay unit, am I right in thinking this is probably relying on the fail-safe position of the valve?

 

[Newboy]

1) Buy a new (Honeywell) thermostat and pair it with the existing relay. http://www.honeywelluk.com/homeowner-zone/resource-centre/Product-Brochures/

2) Deduct the cost of the replacement thermostat from the deposit!

3) The relay has gone into failsafe mode and is allowing heating without the thermostat signalling demand (which is good but needs to be sorted unless you want the heating to run continuously)