What's the asterix setting on a trv for?

* Frost setting , when temperature gets down to about 7 degrees heating should come on.

 

TRV will not switch on the boiler, the * setting will just allow that radiator to warm up when the frost temp in the room is detected. But only if the boiler is on already.
You are also correct, TRV's next to thermostats are a bad idea.
And TRV's definitely do not switch on radios JZ2011 - unless you've found a new product - in which case post it here quickly!

 

I lost that sentence & didn't spot it was missing.

Using a compact keyboard, & somehow I'm deleting paragragh/sentence I've type.

 

Yes the room with your theromostat is normally the room with your (heat soak) radiator with 2 lockshields (normal valves) to allow flow through if all the trv's close down it's usually the hall way but have seen towel rads as heat soaks,

You can now get trv's that have digital readouts on them and can set them to turn on the boiler via the controller if needed

 

You're right DNR, I'd forgotten about the Honeywell Evohome.

Has anyone installed the Evohome? Only reason for asking is my experience of it was that it was very unreliable. A new customer of mine had it taken out as it was picking up random signals at all hours with the boiler firing up to heat odd radiators - drove the customer up the wall. He even had Honeywell out and they updated some software, but although better it still fired up at odd times.

 

Yeah the boiler fires for 1 rad but heats them all so not very efficient at all I would prefer a correctly sized system without trv's but it's not the modern way I guess

 

Agreed - all this RF stuff seems fine initially but longer term reliability is questionable. I've had any number of calls to these systems with problems ranging from a simple re-set and battery change to a completely failed unit - usually just months out of the guarantee period

 

A well balanced thermostatically controlled system set at a good set point in a well insulated property with correctly sized boiler and radiators is the way to go in my humble opinion but not often implemented correctly

 

Back to the OP. The frost setting will keep the valve slightly open. If you want to remove the radiator, first remove the TRV handle and use a decorators cap which will completely depress the pin and shut the valve completely.

 

Who can ever find a decorating cap?? That's why most trv's also have an off