Hi guys, I have a fault on a clients heating system whereby the heating will stay on regardless of what the programmer is doing on its timed function, it'll switch off at the programmer (no light) but boiler will stay on until they turn the stat down, I went and looked at it, they said they weren't sure whether it's ever worked correctly on timed function (handy) it has a Honeywell 2 channel programmer and a Honeywell wireless non programmable room stat not the same models, I thought it was because it had been linked out incorrectly at the receiver unit on the stat, I tested it on its timed function and it switched off and on and so on after removing the weird link and thought happy days, but now they called me back after a day of it working fine saying it continues to stay on even when the programmer is set to auto but off time, saying it came on middle of the arvo? Thinking about it.. (I'm now confusing myself) - are the programmer and stat even compatible, as the wireless stat is constantly supplied a live connection and can essentially switch the zone valve independently of the programmer. The programmer is st9400c and a Honeywell wireless stat and receiver (circular one that looks like a nest). Could someone more electrical savvy than me shed some light as to how it's supposed to be wired, I understand s plan wiring etc but this has really confused me. TIA