Boiler won't come on unless triggerd by cylinder thermostat
- Thread starter keshdevon
- Start date
Sponsored Links
A 'Y' system uses a 3 port mid position valve so you can have CH only or HW only. Or you can have them both on together, although in this situation as soon as one side becomes satisfied, the valve moves to fully open for the side not yet satisfied.
There is something amiss if your programmer does not cater for CH only.
A system with the correct parts fitted and wired correctly, that gives the fault described indicates a fault within the actuator head.
As already stated the valve may be stuck or not go beyond mid point, or even if it does go the CH position a faulty micro switch within the head will prevent the boiler from lighting.
When HW is involved power to light boiler comes from cylinder stat. When HW is not involved power to light boiler comes from the valves 'orange wire' via micro switch.
There is something amiss if your programmer does not cater for CH only.
A system with the correct parts fitted and wired correctly, that gives the fault described indicates a fault within the actuator head.
As already stated the valve may be stuck or not go beyond mid point, or even if it does go the CH position a faulty micro switch within the head will prevent the boiler from lighting.
When HW is involved power to light boiler comes from cylinder stat. When HW is not involved power to light boiler comes from the valves 'orange wire' via micro switch.
to me its another pump.
Danfoss Randall 102/103
Sponsored Links
Looks like a circulator to me too, with speed control on the side.
That said, where is the heating flow pipe.
No, just know that not all systems give independant heating only.
Can you take a wide angle photo and use the diynot link so we can enlarge
Its an SMC twin pump system. When there is a call for hot water, the hot water pump runs and turns the boiler on. If there is a call for heating, the central heating pump runs and an electrical relay turns the boiler on.
Nice one Mike
Its an SMC twin pump system. When there is a call for hot water, the hot water pump runs and turns the boiler on. If there is a call for heating, the central heating pump runs and an electrical relay turns the boiler on.
whats the idea of that sort of system then ? never seen one before.
N
namsag
Check that both the pumps are running the blue one runs for HW and the other one runs for CH sounds like gold one is not running Take the centre screw out and check spindle is spinning.
EDIT..
Just re read and you said you can hear pump so it sounds like a relay fault. Take the cylinder stat off and you will get CH just be careful as water will be hot coing out the taps
Seco you won`t see any off these basically its the same as a grundfoss pump plan. If you look the pump has 3 ports straight through for the heating with a top exit for the hot water , Ther is usually a non return valve fitted to stop the heating coming on when just the HW pump is on
EDIT..
Just re read and you said you can hear pump so it sounds like a relay fault. Take the cylinder stat off and you will get CH just be careful as water will be hot coing out the taps
Seco you won`t see any off these basically its the same as a grundfoss pump plan. If you look the pump has 3 ports straight through for the heating with a top exit for the hot water , Ther is usually a non return valve fitted to stop the heating coming on when just the HW pump is on
Here are the pictures
[GALLERY=media, 8222][/GALLERY] [GALLERY=media, 8223][/GALLERY]
Thanks for the diagram swbjackson.
So the CH pump is the blue one and the brown/bronze pump is for the hot water right?
The brown/bronze one seems to work - makes lots of wooshing noise when its on!
So if the call for heating from the room thermostat in my lounge isn't triggering the boiler then there is a fault in the wiring of the controller of the CH pump? Is there still a valve inside it that might be stuck?
Do you think it is easily fixable- or should I just put up with it till spring then get the whole lot replaced?
[GALLERY=media, 8222][/GALLERY] [GALLERY=media, 8223][/GALLERY]
Thanks for the diagram swbjackson.
So the CH pump is the blue one and the brown/bronze pump is for the hot water right?
The brown/bronze one seems to work - makes lots of wooshing noise when its on!
So if the call for heating from the room thermostat in my lounge isn't triggering the boiler then there is a fault in the wiring of the controller of the CH pump? Is there still a valve inside it that might be stuck?
Do you think it is easily fixable- or should I just put up with it till spring then get the whole lot replaced?
N
namsag
Can you take the cover off the black junction box so can see the wiring to double check which puMp is for HW
DIYnot Local
Staff member
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local
Sponsored Links
