Can you clever lot help me fathom out our hot water??

jefaz07

You have a Y plan. The F&E tank in the loft (above) will fill the tank from the bottom as you use it. 

When the cylinder stat drops below the set temperature and the programmer is set to HE the mid position valve will open on the HW side only. This will allow water from the boilerzzzthrough the coil in the cylinder and back to the boiler. 

Staffordian11

The mid position valve shown in your pictures is designed to open and close valves, in order that the hot water from the boiler circulates only round the radiators (H for heating), only through pipes within the hot water tank to heat the water  (W for water) or through both at the same time to provide both heating and to heat the water in the tank at the same time.

It should move in response to how your controller is set, and I think the tab on the mid position valve shows you how it is currently set (H for heating in the photo). The motors in these valves often fail, and I think you can manually switch between modes by moving the tab, which usually springs towards one position but can be pushed the other way and it should latch in the other positions.

You also have a thermostat on the tank, which should be connected to the boiler so the boiler stops firing once the hot water reaches the set temperature.

All the above assumes the system has been set up in the standard way, and is working. You probably realise, but it is work mentioning, that if your tank is cold, it will take quite some time for the boiler to heat it as it relies on transferring heat from a coiled pipe inside the tank into the water.  It's not like a combi boiler which actually heats the water which then comes out of the hot tap. When we had z system kike this, we set the water to come on for about an hour each morning.  You should be able to check if the boiler is heating the water when you set it to do so. There will be a pipe from the mid position valve going into the tank. This should be hot, then a second pipe should emerge from the tank, which should be cooler, as the heat has been transferred to the water in the tank. If it's cold when the tab on the valve shows either W or M , it suggests the mid position valve itself is jammed and is only allowing water through the radiator circuit.

GrumpyDil

Or in simple terms if the heating is off and water on and the boiler is firing up it's very likely to be heating the tank. Give it a little time and then you should find you start getting hot/warm water again. 

MakingUpGround

It was the heating firing up. I turned the heating on the right of the control to off, and the water to on, but the heating has been on mega hot for the past hour when usually it would be off

Staffordian11

MakingUpGround said:

It was the heating firing up. I turned the heating on the right of the control to off, and the water to on, but the heating has been on mega hot for the past hour when usually it would be off

Sounds like that mid position valve is either not connected, or not working.

With the controls set for water on and heating off, the tab should be by the W. If its not, then see if the tab on the valve can gently be moved manually to the W position. If it moves, see if it springs back to H. If it does, move it back to W and gently move it sideways to see if it will latch into this position. If it does, this should have opened the valve to heat the water. If it doesn't then there is likely a problem with the innards of the valve. Plumber time!

MakingUpGround

Staffordian11 said:

MakingUpGround said:

It was the heating firing up. I turned the heating on the right of the control to off, and the water to on, but the heating has been on mega hot for the past hour when usually it would be off

Sounds like that mid position valve is either not connected, or not working.

With the controls set for water on and heating off, the tab should be by the W. If its not, then see if the tab on the valve can gently be moved manually to the W position. If it moves, see if it springs back to H. If it does, move it back to W and gently move it sideways to see if it will latch into this position. If it does, this should have opened the valve to heat the water. If it doesn't then there is likely a problem with the innards of the valve. Plumber time!

yes the value doesn't move. so I need to get a quote to replace this if we want to use it. You guys appear to be saying it will be cheaper for us in the long run if we had this fixed? 

Verdigris

You guys appear to be saying it will be cheaper for us in the long run if we had this fixed? 

Definitely. I suspect, when the valve went wrong, somebody just switched the immersion on, as a quick and dirty fix, and it's been the same, ever since. May have cost enough to buy a new central heating system, over the years!

MakingUpGround

luckily we've only been here 4 years, so hopefully not too bad for us. I didn't actually think our elec bills were too bad! 

MakingUpGround

This is a daft question, but should it be an electrician or Plummer to replace this switch? This is the one we are talking about isnt it? 

Gerry1

MakingUpGround said:

This is a daft question, but should it be an electrician or Plummer to replace this switch? This is the one we are talking about isnt it?

You may find it's easy enough to fix it yourself, it may just be jammed.  Only do so if you're comfortable with the basics of electrical safety.  Make sure you switch everything off at the consumer unit or fusebox, and then try some gentle taps with a soft hammer or equivalent.  Trying to move the mechanics, possibly assisted by a squirt of WD40 may do the trick.  With a cool or cold tank, turn the wick up on the HTS3 thermostat, and get the boiler to fire up.  With the power restored and keeping clear of live terminals, if you turn the thermostat down and up (listen for the click each time) you should be able to see the gearwheel and the gubbins move each time the thermostat clicks.

Plumber is probably better to avoid leaks etc.  The motor may well be reusable, but even if you need a new one the electrical connections probably use twist connectors and the existing ones can be re-used, so the electrical work is not significant.