Electric radiators with Evohome

[filbert]

We've got a small WC heated by a 700 watt oil filled radiator, controlled by a time switch. Having a spare BDR91 and a round stat (YR somthing), I thought I could add it to my Evohome setup. I can't currently search here but I'm sure this sort of thing has come up before. I see that Resideo don't recommend it. Also, 700 watts is pushing the 3A limit for the BDR91 (or is it 5A, I'm not clear about that).

Anyone any experience to offer?

[StuartW]

Until recently I was doing just this with a 2KW oil filled radiator in our garden office.

I've added this relay across the output of the BDR91, which it turn switches the radiator on/off. Added to EvoHome as an electric zone with external sensor.

[bruce_miranda]

700w is about 3A. The BDR91 is rated for 5A. So you should be fine. Anything higher than that would require another contactor relay.

[filbert]

700w is about 3A. The BDR91 is rated for 5A. So you should be fine. Anything higher than that would require another contactor relay.

Thanks. I'll give it a go.

[filbert]

Until recently I was doing just this with a 2KW oil filled radiator in our garden office.

I've added this relay across the output of the BDR91, which it turn switches the radiator on/off. Added to EvoHome as an electric zone with external sensor.

Thanks. I'll bear that in mind. Is the relay coil 240v? I couldn't work it out from the datasheet.

[StuartW]

Thanks. I'll bear that in mind. Is the relay coil 240v? I couldn't work it out from the datasheet.

Yep.

(some other words to meet minimum post length)

[G4RHL]

Sometimes there can be a surge of power on switch on which relays can’t cope with and they weld together. Usually it takes quite a surge though. I had this with smart plugs. In the early days fluorescent lights could “blow” them. I had a particular PSU that did it. I get gear to try from one well known body and was sent their smart plugs before general release. I deliberately set about seeing how robust it was - the supplier knew I was doing it! After a week or so it stopped working, as expected. I got a free replacement (two in fact!). It is the initial surge that can cause the problem. Therefore, it may be using the Evohome gear all works well at first, but in time the initial current drain is too much.

On the subject of electric radiators it bugs me that our government is besotted with pushing surface heat pumps and providing large grants for them when for about the amount of the grant you could fit a full electric heating system in most houses. In my case, a 4 bed detached, I know it would cost me about £5000. An easy DIY installation that needs no maintenance. Problem is the running cost. Government needs to subside that instead of heat pumps until production costs come down. I suspect the heat pump and wet system industry is managing to lobby and persuade government on this subject in order to maintain its own business. Sorry I have moaned!