Vaillant Boiler 831 thermostat broken - how can I stop it freezing while we are away?

[WendyFrome]

We have a vaillant 831 and the thermostat is broken so that the heat-call isn't received by the boiler. Nothing happens. I think it probably happened when our 5 year old dropped it a week ago. The thing is we are supposed to go away tomorrow for 10d (for super safe low key Christmas with my parents - we've isolated for 10d to be able to go without taking the virus.) I'm worried about leaving the house without heat but I THINK from the manual that the Vailllant 831 will override the thermostat if temperature drops too low in the water in the system and will heat them up to avoid freezing? Have I got this right?

Read more: https://www.diynot.com/diy/threads/vaillant-831-not-working.559457/page-2#ixzz6gufDJHur

 

[CBW]

What thermostat is it?

 

[WendyFrome]

salus rt 300 rf. Hot water and chimney sweep mode work.

 

[CBW]

Has the screen gone blank, or is it just non responsive?

 

[WendyFrome]

the thermostat does its thing and tracks the temperature and calls for heat. But the receiver doesn't register anything. There is no green light. The red light is steady. Have tried resetting, off/on and replacing with brand new batteries, hence suspecting that we've just bashed something essential in the thermostat.

 

[muggles]

The frost protection in the boiler is just there to protect the boiler - it won't stop the pipes freezing in your house. You'd be better off having a new stat put in

 

[WendyFrome]

Ok thanks

 

[terryplumb]

If your really worried about freezing ,leave heating on low. Alternatively close main stopcock and drain down taps.
And drain the central heating system.

 

[WendyFrome]

thank you

 

[oldbutnotdead]

Have you checked the channel select links in the thermostat are still the same as those in the receiver? (A good battering by a child might be enough to shake one loose).

 

[WendyFrome]

good thought thank you