Home |
Search |
Today's Posts |
|
UK diy (uk.d-i-y) For the discussion of all topics related to diy (do-it-yourself) in the UK. All levels of experience and proficency are welcome to join in to ask questions or offer solutions. |
Reply |
|
LinkBack | Thread Tools | Display Modes |
#1
|
|||
|
|||
Central Heating Pump problem
Dear All,
My domestic Central Heating Pump is running continuously despite the fact that the CH mode on the Landis & Gyr mini programmer is switched off. The only method of switching the pump off is to disconnect the electrical supply at the local junction box. Not a particularly good method. Can you point me in the right direction please and advise the heirachy of the control system. By this I mean, does the programmer have the sole control of the central heating pump by virtue of the CH mode? The system also has 2 off 2 port motorised valves. Advice gratefully received, Regards Mark A Shaw |
#2
|
|||
|
|||
wrote in message
oups.com... Dear All, My domestic Central Heating Pump is running continuously despite the fact that the CH mode on the Landis & Gyr mini programmer is switched off. The only method of switching the pump off is to disconnect the electrical supply at the local junction box. Not a particularly good method. Two things: 1. The pump will probably be needed in HW mode as well as CH. 2. If you have a vaguely modern boiler, it will probably be controlling the pump itself, so that it can do a run-on after the burner shuts down. The relay in mine sometimes sticks, leaving the pump running. A good slap on the side of the boiler sometimes fixes this. (No s******ing, please) Will |
#3
|
|||
|
|||
In an earlier contribution to this discussion,
wrote: Dear All, My domestic Central Heating Pump is running continuously despite the fact that the CH mode on the Landis & Gyr mini programmer is switched off. The only method of switching the pump off is to disconnect the electrical supply at the local junction box. Not a particularly good method. Can you point me in the right direction please and advise the heirachy of the control system. By this I mean, does the programmer have the sole control of the central heating pump by virtue of the CH mode? The system also has 2 off 2 port motorised valves. Advice gratefully received, Regards Mark A Shaw Has it ever worked properly? Does the boiler fire as well, or is it just the pump. If it hasn't ever worked, and is just the pump, it could be wired wrongly. It sounds as if you have an S-Plan system. [See http://content.honeywell.com/uk/homes/systems.htm and scroll down to S-Plan] In an S-Plan system, the programmer and thermostats control the motorised valves (one for HW and one for CH). Each motorised valve has an independent set of contacts which close when the valve is open. These are used to control the boiler and pump. When everything is wired correctly and working properly, the boiler and pump *only* come on when either or both circuits are demanding heat. One variation to the standard wiring can occur if the boiler required pump over-run. That is, if the boiler needs the pump to continue running for a little while after it stops firing, in order to carry away the residual heat. In this case, the pump will be controlled by the boiler, and will be connected to the boiler's 'pump' terminals rather than just being wired in parallel with the boiler, as per the Honeywell diagram. If this is true in your case, there is a possibility that something could have gone wrong with the boiler's pump control logic - causing the pump to run all the time. Let us know what you find! -- Cheers, Set Square ______ Please reply to newsgroup. Reply address is invalid. |
#4
|
|||
|
|||
In article .com,
wrote: My domestic Central Heating Pump is running continuously despite the fact that the CH mode on the Landis & Gyr mini programmer is switched off. The only method of switching the pump off is to disconnect the electrical supply at the local junction box. Not a particularly good method. You should have a method of isolating the heating electrical circuit. A double pole FCU is the normal way. Can you point me in the right direction please and advise the heirachy of the control system. By this I mean, does the programmer have the sole control of the central heating pump by virtue of the CH mode? The system also has 2 off 2 port motorised valves. Since that sounds like a fully pumped system, there must obviously be (auto) switching between the room stat and cylinder stat in their control of the pump. These are commonly microswitches operated by the valve and can fail, or the valve isn't moving to the full extent to operate the switch. Other possibility is the boiler controlled pump over-run circuit if there is one fitted. -- *I have my own little world - but it's OK...they know me here* Dave Plowman London SW To e-mail, change noise into sound. |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Central Heating problem | UK diy | |||
Water Pump / Pressure Tank Problem !!!!!! | Home Ownership | |||
Central Heating - Problem with 3 way valve wiring. | UK diy | |||
Central Heating problem - 2A fuse blowing in honeywell wiring box | UK diy | |||
Central Heating Pump | UK diy |