Is this a 3 way valve problem?

[peedah1]

I have a E tech s 240 boiler that was installed in my 3 year old flat.The boiler is connected to a Salus EP100 programmer. It's a tank in tank, electric, unvented thermal store system, as far as I can gather from reading stuff online.

We can only get the boiler and it's built in tank to heat up if we activate the HW circuit. Whilst this is happening, if we activate the CH circuit simultaneously, the radiators warm up as expected.

However, if we activate only the CH circuit, even with hot water already stored in the tank in tank, the radiators do not warm up... The outflow pipe from the boiler for the CH circuit gets noticibly warmer, but the radiators do not. Activating the CH circuit when the domestic tank is cold does not cause it to start warming up and circulate heat either. I can hear the pump working with either circuit.

A chap from Pimlico Plumbers has already been to examine the system but didn't seem to have a grasp of the problem. He tested the electrics and said all was OK, then told us the problem was the summer/winter switch on the front of the boiler, which it was not! So rather desperate for some help!

 

[gas4you]

First impression from here would be the valve actuator. Needs testing with a multimeter, which I assume the plumber from the 'ones who look after the rich and famous' had and used?

 

[peedah1]

OK, some more testing done... The valve (which I think is 2 way rather than 3) appears to be working as it should. It looks like the pump is to blame - but not because it isn't working... it just won't come on when the CH is switched on. It works perfectly when you turn on the HW, pumping the water around the outside of the inner tank in a loop. So I guess that means there's something wrong with the wiring... unless there's a common cause of this kind of problem?

 

[peedah1]

First impression from here would be the valve actuator. Needs testing with a multimeter, which I assume the plumber from the 'ones who look after the rich and famous' had and used?

Yes he did get his multimeter out. Not totally sure he knew what it did!