Heating fine but no hot water

[peter1982]

Hi,

I'm trying to save money by not using the electric immersion heater, which is on permanently at the moment. The trouble is that when I switch the immersion off and put the gas boiler on I never get any hot water, even after waiting overnight.

I think I have an indirect heating system like this:
http://www.plumbingpages.com/featurepages/HWindirect.cfm

I've uploaded some images of the cylinder here:
http://s300.photobucket.com/albums/nn7/beltv189/

There is a device called a 'mid point actuator' (Drayton MA1) which I'm thinking may be faulty. The pipe going into it is red hot, but the pipe on the other side gets colder the closer it gets to the cylinder, so I guess the heat is being conducted through the metal rather than water actually getting through.

Also, there are several radiators downstairs that heat up although the central heating is off. What's that all about?

If I have to get the mid-point activator changed, how much would that cost me, including labour?

Please help!

Peter.

 

[kevplumb]

the pipe sticking up behind the valve is an air vent open this first and see if its just an airlock in the cylinder

 

[peter1982]

If you mean the L shaped pipe behind the actuator going off to the left, then that is a cold water pipe going to the electric shower in the bathroom next door. No sign of an air valve.

Is it worth me taking the cap off the actuator and taking a look around? In what way do they die? Is there any minor maintenance I can do to it? As I said, that actuator is a Drayton MA1...



P.

 

[kevplumb]

If you mean the L shaped pipe behind the actuator going off to the left,

no the one with the end stuck up in the air on the pipework between the valve and the cylinder View media item 382 this one

 

[peter1982]

OK,

I tried the air lock and there was very little air in it. Water came out very quickly. I'll run the system to see if it had any effect though...

Thanks,

P.

 

[kevplumb]

try moving the lever on the actuator and locking it

 

[D_Hailsham]

I think I have an indirect heating system

Correct. You have a Y-plan system.

Is this a new problem or have you always used the immersion heater and only discovered the problem when you turned the immersion off?

There is a device called a 'mid point actuator' (Drayton MA1) which I'm thinking may be faulty. The pipe going into it is red hot, but the pipe on the other side gets colder the closer it gets to the cylinder, so I guess the heat is being conducted through the metal rather than water actually getting through.

Looking at your pics I think the Drayton valve has been put in the wrong way round. The ports on the valve should have letters stamped on them. The inlet should be stamped A/B; the one to the HW cylinder stamped B and the one to the central heating stamped A. It looks as if the HW and central heating connections are reversed. This will stop the valve working properly.

Read Mid-position valve working and Diagnostics.

If you turn your central heating off, will the HW heat up OK?

 

[peter1982]

try moving the lever on the actuator and locking it

How do I do that? Here's the MA1...

I can see a large black button on the front, on the left hand side there is a switch with three settings (H M W) and on the right a small black button. Which ones do I use?



P.

 

[peter1982]

Is this a new problem or have you always used the immersion heater and only discovered the problem when you turned the immersion off?

No, this is an old problem. The house is four years old and we have lived here for a year. We have always had to use the immersion for hot water. But with energy prices going up I thought it was about time to economise, hence wanting to get to the bottom of this problem...

If you turn your central heating off, will the HW heat up OK?

I don't know. I'll give that a go. Thanks.



P.

 

[peter1982]

Looking at your pics I think the Drayton valve has been put in the wrong way round. The ports on the valve should have letters stamped on them. The inlet should be stamped A/B; the one to the HW cylinder stamped B and the one to the central heating stamped A. It looks as if the HW and central heating connections are reversed. This will stop the valve working properly.

I checked the valves and they seem to be the correct way round:
- A to central heating
- B to hot water cylinder

P.

 

[D_Hailsham]

I checked the valves and they seem to be the correct way round:
- A to central heating
- B to hot water cylinder

Sorry for the red herring

I took a quick look at your pics and thought I could see the HMW lever on the front as in the latest versions (see Drayton Motor Valves. Your HWM is on the side.

The HMW lever is not a switch, it is just an indicator to show which port is open (I'll let you work out what H, W and M mean )

If you can get the Hot Water working when the central heating is turned off, you should check the wiring to the thermostat on the side of the cylinder. There are three connections and all have to be connected.

Click on the picture below to see a larger version of the wiring
View media item 70