Hi Folks,
Last year, I installed electric undertile heating in the downstairs bog. It was working fine until the spring when I effectively turned it off by turning the temperature down below the ambient. Looking at it this weekend (now the temperature has dropped enough for it to come back on), when I realised the floor wasn't warm, I can see that the thermostat/ programmer senses that the temp is low, cuts the heater in, then almost immediately the display goes blank. After a while, the display comes back on, it waits a while, then goes through the cycle again.
The whole lot came from B+Q (often an error but they had a good offer when I bought it!) and was branded 'Tile-it'. They don't sell that range any more (I wonder if that means something), but I've tracked the programmer down as an Aube TH132 (
The programmer seems to have an over-current cut-out, so I thought perhaps that meant there was a short or earth leakage somewhere in the circuit. Measuring the resistance of the heating circuit gives me 187 Ohms, which seems about right for a 300W heater, by my reading of Ohm's Law. There's no circuit to earth according to my multimeter. It occurred to me that there could be a path to earth under voltage, so (in the absence of any more sophisticated test equipment) I disconnected the earth connection (only for a brief test - don't try this at home;-) but that made no difference to the programmer's behaviour.
Combined with the fact that none of has been disturbed in any way over the past year, this all seems to indicate a duff programmer but there may be something I'm missing so, before I shell out 70 quid for a new programmer (it had a 2 year guarantee, but I can't track down the receipt, so I'll have to swallow the cost of a replacement), does anyone have any good ideas for any other test I can try to conclusively show that there's really some point in replacing it and it's not the heating element or sensor? If it is the element, there's no real practical fix, short of getting the angle grinder out!
Thanks for any tips