What happened?

:confused: My greenhouse max and min thermometer is showing a minimum temperature of -7 degrees. This is 1degree warmer than the outside min. temp. reading. We had 2 very cold days one of which was boxing day, when I was away and did not check the greenhouse next day either. I am wondering if there might have been a power cut either on that day or during the night, as last cold spell green house temp. went down to -1 degree when outside temperature was -6 degrees, and I then turned it up slightly from frost free setting.
I think it's too early to tell if anything has suffered, all looks OK.

 

I know this might not be the answer, but a problem I have found with one of those RCD thingies, is that it has to be reset after a power cut, ie. when the current comes back on, my heater doesn't.
Has anyone else had a similar problem?

 

My heater was on when I checked, so I was lucky there. I was wandering if the heater was simply inadequate for the size of the greenhouse, but it coped for the first cold spell.

 

How big is the greenhouse?
What is the wattage of the heater?

 

Greenhouse is 6' by 8'. Will have to check wattage tomorrow!

 

Okey-doky, sounds like it should be OK as long as its 2kw+.
There is a formula I think for working it all out but I cant remember it. :(

 

Just a thought, if its got more than one element, which I think it might well have, one could have burnt out.

 

Liz if the heater is working properly now and didn't need resetting of the RCD - sounds to me like you may have had a power cut - even the small heaters will keep a 6x8 greenhouse above freezing in my experience.

Have you any timer device you can take a look at and check - my heating timer, and my electric garden lights show if there's been a power cut long enough to allow the temperature to drop that low. We have frequent power cuts here - though usually not off for long - its never tripped my RCD.

A lot of tender plants will survive a temperature drop below freezing, as long as it is not too long. So fingers crossed all will be well.

[ 01. January 2006, 10:05 PM: Message edited by: Fran ]

 

I examined the heater closely but it has no rating on it. It's an old one that my Aunty used in her green house, but in very good nick. I haven't any timers... not very efficient at all. Have you any advice about where to buy timers and /or usage meters?

 

Cant think why you need a timer, if its cold you need it on, wether its day or night, so I only use a thermostat.
Think Fran means electric clocks which dont reset automatically after a powercut. They would tell you if there was a powercut.

 

Abject apologies for not being clear - by checking timers I meant on other appliances like the central heating etc to check if a power cut was the problem. For the temperature to drop that low, must have been off for a little while.

Glass house heaters are best thermastatically controlled.

Sorry Liz

 

Maybe the thermostat's on it's way out, and occasionally sticks.

 

I can't find anyone in my road who knows of a power cut, but most were away. So you may be right, Rich. I shall have to check it more closely when temperature drops again. I can't think of anything else, the thermometer is new, and anyway it's a mercury one so I can see it's not broken.
Thanks everyone for the suggestions!

 

hi everyone where can i buy one of these heater thingies and how much are they.

 

www.twowests.co.uk
Have a look here, I've used them before, and they are pretty good.