Heating/Boiler Problem

Leoki · Oct 7, 2009

Help please, i put my central heating on for the 1st time since winter just to test everything was okay. After a short time i noticed that the hot water from the DHW cylinder was very hot, hotter than the 60 degrees the cylinder thermostat is set too. Also noticed that the radiators were still hot (like a sauna in the house) even though the room thermostat downstairs was set to just 15 degrees. I turned the central heating off at the programmer but the radiators continued to be hot. I then turned off the hot water at the programmer but the boiler continued to run until i manually shut it down.

Any thoughts. I think i may have a programmer issue. The cylinder thermostat should have stopped the DHW getting above 60 degrees and the room thermostat should have shut down the central heating. It is though i have no boiler interlock ?

Puddle · Oct 8, 2009

well first thing to look at is to see if your heating motorized valve is stuck in the open postion

hot water would have got hotter than normal as maybe hot water valve slightly by passing,when heating on

Leoki · Oct 8, 2009

Puddle, thankyou. How do i check the position of the valve ?. I have had a look around the outside, there is a lever on the side casing, i think this lever is used to open the valve to the mid position when intially filling ?. Is this what i would check to work out the valve position ?

Puddle · Oct 8, 2009

I take it you have two motorised valves ,one for heating and one for hot water,if this is the case ,then when everything is off when you pull lever across,you should feel resistance of the motor ,if you do not then the motor is stuck in open position causing problem

Leoki · Oct 8, 2009

Puddle, thanks again for responding. I have a 3 port mid position vavle. It has a small lever on one side which i recall reading is pulled back to the mid position when the system is first filled.

Puddle, i have just tried to move the small lever on the side of the port and it is stuck in position, it will not travel the length of the groove that you can see, i take it this means the valve is stuck in the mid position ?

Puddle, have now cracked it, thanks for your input. New actuator head fitted and CH & DHW now back to normal.

Many thanks, Leoki