Need help with faulty heating please

[BiggRuss]

Hi, I hope someone can help. Now that the waether has taken a turn for the worse i have got the heating system on again and i have a problem.

Basically what happens, altough not always, is when the heating comes on it works fine, but every now and then it won't turn off when I have programmed it to, and soemtimes when it runs it ignores the thermostat and keeps running even whent he room is up to temp, which would be nice in the winter, but as its not that cold and it is just needed to take the chill out of the air at night it ends up like a sauner in my house. The only way to stop the heating is to turn off the main power to the heating system, which is a pain as the only switch is in the garage on the main fusebox (another job for layer is to add a switch for it next to the programmer).

My system cocsists of a standard boiler, hot tank in the airing cupboard with the programmer there too as well as a mi position valve there with cold and expansion tanks in the loft.

Do you think it is likely to be the programmer that is faulty or the mid position valve or another problem.

also what was happening in the summer was that when we had just the hot water on the radiators where getting hot as well, not as hot as they do when the heating is on, but quite hot.

is this likely to be related, or as my mate that knows a little about plumbing thinks, is an unrelated problem to do with the way the system was piped up when first installed. I only moved in last year and inherited the system so don't know how old any of it is.

Any help would be appreciated, my girlfriend is constantly on at me to get it sorted and i cant stand her nagging for much longer

 

[seco services]

sounds like you have a faulty actuator/microswitch on your mid position valve.
hot rads in the summer when heating off is a bypassing valve or reverse circulation if you suspect a pipeing problem.

what make/model valve is it ?

 

[BiggRuss]

the only branding i can find on the valve is "ACL" and "Lifestyle"

which is the make and which is the model i have no idea, thanks for the reply anyway.

my mate thinks the pump is on the the wrong side of flow/return and thinks it may be sucking air a bit thru the overflow pipe to loft and may be why system is a bit noisey and gurgly ,which i am going to get sorted soon, sould this be the cause of the hot rads in summer as well?

 

[seco services]

have you any pic or diagram of this system ?

 

[BiggRuss]

no i don't, sorry. maybe i should reword it a bit. my mate thinks the overflow/expansion pipe, whatever it is called is on the wrong side of the flow/return, or the pump, i forget what he said now. the pump is above the boiler. the pie he is on about is in the airing cupboard and goes up to the expansion tank in loft. i forget if it is the pipe that hangs over the top of the expansion tank that is wrong or the one that is actually conected to it. the one that hangs over the top is teed in just after the 3 way valve, the one that is connected to the expansion tank in loft is conected to the lower of the 2 pipes coming out of the hot water cylinder, whcih i think is the return, and again puts it after the 3 way valve. I think he said it should be on the other side

 

[seco services]

the best combination is vent-coldfeed within 150mm of each other then pump-valve all on the flow from boiler.
but this isn't causing the hot rads.
thats another issue

 

[MANDATE]

I also think it is valve related.
I'm thinking your problem may be due to a stiff/stuck spindle in your 3 port valve.
In the actuator head there is a spring. When HW only is selected, the wire that kept the motor energised at the CH only position becomes dead. It relys on the spring to push the motor in reverse right back to the HW only position. If the spindle is stiff/stuck and opposes the spring, the valve may stop or stuck somewhere near mid position.
This would mean, even though you have selected HW only, water would be going to both HW and CH.
I would be be looking at removing the actuator head off the valve spindle (if it is removable) to check the spindle.
When testing I would avoid selecting HW and CH together, the fact both are switched on does not mean the valve stays in the mid position and this causes confusion.

In HW only position, feel pipework each side of valve. If pipe to CH is hot, then valve is a problem.

Likewise in CH only position, feel pipework again. If pipe to HW is hot valve has problem. If boiler lights up in this position, you know the microswitch is not a problem.