Weather compensation DIY outdoor sensor

[palpable]

I have a gas CH boiler capable of weather compensation. The official Remeha outdoor sensor costs upwards of £70, while one for an Ideal boiler costs more like £25.

I'm tempted... but then on Ebay an indoor/outdoor thermometer with LCD display and all sorts of bells and whistles costs under a fiver.

So (being cheap) my inclination is to go DIY, but searching the web has failed to produce any info on what the 'outdoor sensor' actually is, how it works or how I can make one.

I'm tempted to just butcher an indoor/outdoor thermometer, connect the outdoor bit up and see if it works, but I thought I'd ask here first, cos someone's bound to know more than me

Has anyone played around with this?

 

[D_Hailsham]

The official Remeha outdoor sensor costs upwards of £70

BHL are selling them for £25.02. (Shown as Broag outdoor sensor.)

The sensor is a NTC thermistor in a weatherproof case with attached cable.

You can't use any thermistor; it has to have specific characteristics to match the internal program of the boiler.

 

[Agile]

Virtually all boiler sensors are a nominal 10k.

Your boiler manual should show this.

A sensor element is only about 32

Tony

 

[palpable]

fantastic, thanks very much to you both. That's a much more sensible price than I'd found, so I'll go with that and avoid all the calibration issues I was talking myself into.