Central heating but no hot water

[dbscubadiver]

My house is about ten years old and I moved in during 2014.

In the last 2/3 months I had a suspicion I had developed an electrical fault as I have had problems with getting hot water. I could turn on the central heating and a 'C' status would show on the boiler in the kitchen but nothing would happen with HW.

We thought it was the Sunvic programmer so my dad and I replaced it yesterday with a Honeywell ST9400C . I re-programmed the times to suit but the hot water still isn't coming on but I am sure when we checked it using the factory set times it was fine.

I have attached a picture of the tank in my airing cupboard (the pressure is currently at 1.4).

I know the black box is the pump and the white box bottom left is the thermostat but what are the other three and would any of them need replacing?

A basic intro would be very helpful.

Thanks,

 

[dbscubadiver]

I think I have discovered the left hand box is the MV for the C.H. and the other is the MV for the H.W.

I turned the central heating on in the kitchen and I could feel the valve turning in the airing cupboard only after I wriggled around with it which suggests to me the electrical connections in the junction box need checking.

 

[jackthom]

If there is a lever on the valve for HW try operating it manually and check that the boiler then fires up. It may just be a sticky valve causing the problem or it’s motor may be on the way out.

 

[dbscubadiver]

Thanks. There doesn't appear to be a lever but there is a red dial. Would that be the same thing?

This is what I have:

http://www.seered.co.uk/sunvic_casing.JPG

 

[jackthom]

I haven't played with one of those valves but hopefully you should be able to operate the thumbwheel to open the valve.

 

[dbscubadiver]

I turned the C.H. on again and I have noticed the red wheel rotates. I turned on the H.W. and managed to get it's red dial turning for about 2 minutes and then it stops. So I am now also beginning to think the motor is on its way out.