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More Info. |
Here are a few points on electrical installation. Pipe stat. Ideally, the pipe stat should be mounted on the return at the solid fuel boiler. However, if this is impracticable, it can be mounted on the same return pipe but at the neutralizer. The pipe stat temperature should be set to the same temperature as the cylinder stat.
Boiler on/Boiler Live. Some old oil boilers do not have a seperate boiler on - they simply switch on when power is applied. In this case, the terminal boiler on from the controller should be connected to boiler live and boiler live at the controller left disconnected. Identifying boiler on. Most oil/gas boilers do not have a terminal specifically marked "boiler on". However, the "on" terminal is easily identified. It is the one which connects to the boiler pump live. Other terminals Pipe, room and cylinder thermostats may differ as to connector markings. Pipe stat: pin COM on controller goes to the common terminal, pin NO to the make on temperature terminal. Room stat: pin NC goes to break on temperature, pin N to neutral, pinCOM to common. Cylinder stat: pin C to common, pin NC to break on temperature. Pumped solid fuel boiler. We do not recommend using this system if a gravity feed from the solid fuel boiler to the neutralizer cannot be established. However, it is possible if a gravity fed heat leak radiator can be fitted to the solid fuel boiler before the pump. If this is not possible then under no circumstances should this system be used. In the event of a power cut, the solid fuel boiler could seriously overheat and could explode. If it is possible to fit the heat leak radiator, the procedure is: Move the pipe stat to the boiler feed pipe. Set it to a temperature higher than the oil/gas boiler temperature. This may require a little experimentation but is needed to stop the pump running after the solid fuel boiler has cooled down. Run a wire from the solid fuel pump to the controller. Connect live to pipe stat terminal 2 in paralell with the pipe stat. Connect the neutral to pump terminal N in paralell with the pump neutral. The main drawback to this system is that it will take the hot water longer to heat up when just using the solid fuel boiler.
Commissioning and fault finding. A few simple checks are all it needs for comissioning. Test 1. Switch hot water and central off at the programmer. With the solid fuel boiler cold, turn the pipe stat down until it operates. The central heating pump should operate and the oil/gas boiler should remain off. Turn the pipe stat back till the pump switches off. Test 2. Switch central heating on at the programmer. Turn the room stat up full. The central heating pump should operate and the oil/gas boiler should come on. Turn the room stat back down till the boiler shuts off. Switch central heating off at the programmer. Test 3. Switch hot water on at the programmer. Turn the cylinder stat up full. The oil/gas boiler should come on and the central heating pump should remain off.
If these tests are passed, set all stats to the desired levels and that's it.
Fault finding. If the controller fails all tests and there is power between terminals power L and power N then I'm afraid it's almost certainly mis-wiring. The obvious checks are whether th pipe stat, cylinder stat or pump are cross wired. Also, room stat and boiler. In the event of it passing some of the tests and failing others, set up the conditions for the failed test and measure for live in sequence. Each diagnosis assumes that live was found on the previous terminals but not on the one being measured. Test 1. Pipe stat terminal COM .................................... Faulty controller. Pipe stat terminal NO .................................... Pipe stat set too high or faulty. Pump L ........................................................ Faulty controller.
Test 2. Programmer terminal L ............................. Faulty controller. Programmer terminal CH ......................... CH not on or programmer faulty. Room stat terminal COM ................................. Faulty controller. Room stat terminal NC ................................. Room stat set too low or faulty. Pump terminal L/Boiler Terminal ON ...If there is power on one of these but not the other, the controller is faulty. If there is power on neither, it indicates a relay fault. Check that the relay is properly mounted. If it is, you can either return just the relay or the whole controller. Test 3.
Programmer terminal L .......................... Faulty controller. Programmer terminal HW ..................... HW not on or programmer faulty. Cylinder stat terminal COM ......................... Faulty controller. Cylinder stat terminal NC .......................... Cylinder stat set too low or faulty.
Please note. The relay, being electromechanical, will eventually fail. If this happens, the solid fuel side will continue to function as normal but the oil/gas boiler system will not work. The relay is available from Maplin (www.maplin.co.uk) part no. N13AW 5A 240Vac DPDT.
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