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Heatmiser PRT
Posted: Tue Nov 25, 2008 2:29 pm
by MontyWB
Anyone know how to replace a 25 year old thermostat with a digital one with regard to wiring? I have red, blue and yellow wires to current thermostat and I think I have to connect live to L and A1, neutral to N and yellow to A2 on the PRT. Am I correct?
Posted: Tue Nov 25, 2008 10:54 pm
by plumbbob
You haven't said what model of new stat you have so it is difficult to be precise. Generally on new thermostats the neutral (usually the blue wire) is unused and must not be connected otherwise there will be a big bang.
See this topic
https://www.diydoctor.org.uk/forums/view ... hp?t=14932
Posted: Wed Nov 26, 2008 10:00 am
by MontyWB
Hi Bob
It's a Heatmiser DT / PRT.
I think I have to connect live to L and A1, neutral to N and yellow to A2 on the PRT.
That's how it looks to me from the wiring diagram.
Posted: Wed Nov 26, 2008 12:29 pm
by plumbbob
Yes, looking at it now, you are right. PRT's need the neutral. I thought it was just a standard thermostat and the new digital ones don't use the neutral.