Our combi boiler is controlled by a HoneyWell controller.
When h/w and c/h are set to timed, they both work fine.
If h/w is then set to constant and c/h remains on timed, the c/h appears to remain working even outside of the timed periods. i.e c/h not switching off.
2007-02-17 22:51:21 · 7 answers · asked by Ian G 1 in Home & Garden ➔ Maintenance & Repairs
Sound like a faulty timer or motorised valve, If you have a timer on a combi you must have an indirect cylinder as well? If you have a 3 port valve with mid-position it's probably that, replace it with 2 zone valves, much more reliable.
2007-02-18 03:23:35 · answer #1 · answered by jayktee96 7 · 0⤊ 0⤋
Your C/H units purpose is to satisfy your thermostat (inadvertantly creating a comfortable living climate for yourself) and to do this your thermostat has what is known as an "anticipator". This basically is there to keep the home from overheating/overcooling during cycles. the way it works is that before the actual temperature drops to the call for heat the thermostat "anticipates" the need and calls a bit sooner, on the top end just prior to reaching setpoint the thermostat "anticipates" it will be satisfied and turns the call for heat off allowing the system to recirculate the heated water without adding anymore BTU's by firing the boiler. What may be occuring is the setting for your anticipator may be off allowing the unit to run past its anticipated cutoff point. Look at the thermostats manual to see how to adjust.
A second possible cause may be that with modern Combi boilers a call for DHW (Domestic hot Water) over-rides the call for heat for the duration of the water consnmption. once the water stops flowing the unit returns to its previous cycle. If the unit is set to run on pressure (steam units) then it will run the time set of maintaining that pressure after the call for heat. This adjustment is kind of a combination between the thermostat and the pressuretrols (again steam systems).
If this is not the case , asking the question at a forum frequented by Hydronic experts may resolve the issue for you. I recomend the "Heatin-help" one in the links below as it is solely Hydronics (steam and hot water) orientated.
2007-02-17 23:23:37 · answer #2 · answered by functionalanarchist 3 · 0⤊ 1⤋
Hi i had a similar problem with my central heating working even though the control was set to hot water only. The problem was solved by fitting an anti syphon valve between the boiler and the hot water tank. This is an old system, not one that uses a com-bi boiler.
2007-02-18 00:10:31 · answer #3 · answered by Anonymous · 0⤊ 0⤋
if u got a combi,then u wouldnt have a indirect cylinder fitted??,also if it was a combi u wouldnt or shouldnt have a timer doing the hot water because it should light up when the hot tap is turned on long as theres power 2 the combi,only need timer for heating on a combi????
corgi engineer
2007-02-20 08:12:33 · answer #4 · answered by mickthegas 2 · 0⤊ 0⤋
sound like you have a dodgy timer, but you could try disconnecting the power to it then re connect, 8 out of 10 times this will work thus saving a fortune paying a plumber/sparky
2007-02-17 23:01:34 · answer #5 · answered by amos 3 · 0⤊ 0⤋
It seeems something is at fault with your timer, have a sparky check it out. Oter fault could be a faulty diverter valve. The valve is not closing when switched off.
2007-02-18 03:09:31 · answer #6 · answered by Anonymous · 0⤊ 0⤋
plumber call out time :o((
2007-02-17 22:53:54 · answer #7 · answered by rose_merrick 7 · 0⤊ 0⤋