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Went to a job the other week and it's been bugging me! In the end the boss went to it and diagnosed it as back circulation.
Basically - 3 storey house. Rads on 3rd floor were hot all the time whether heating or dhw was in demand or not. Rads elsewhere were off when not in demand.
I'm assuming the rads on that floor are zoned, they'd have to be, right?
So I start looking for zone valves. Only found one. Only found 1 room stat also. Turned off the programmer and stat and was till getting 240v on the switched live from the zone valve (I replaced the zone valve before I re-tested it).
To me, there is a wiring issue somewhere as shouldn't be getting anything on switched live on the zone valve if the programmer & stat are off. Or the programmer could be faulty (I didn't actually check this at the time for reasons of not knowing how to at the time - I know now).
I am still convinced there has to be another zone valve somewhere.
So, in lamen terms what is back circulation and why would my boss diagnose this as back circulation. It doesn't make sense to me.
Cheers
Basically - 3 storey house. Rads on 3rd floor were hot all the time whether heating or dhw was in demand or not. Rads elsewhere were off when not in demand.
I'm assuming the rads on that floor are zoned, they'd have to be, right?
So I start looking for zone valves. Only found one. Only found 1 room stat also. Turned off the programmer and stat and was till getting 240v on the switched live from the zone valve (I replaced the zone valve before I re-tested it).
To me, there is a wiring issue somewhere as shouldn't be getting anything on switched live on the zone valve if the programmer & stat are off. Or the programmer could be faulty (I didn't actually check this at the time for reasons of not knowing how to at the time - I know now).
I am still convinced there has to be another zone valve somewhere.
So, in lamen terms what is back circulation and why would my boss diagnose this as back circulation. It doesn't make sense to me.
Cheers