central heating prob

[D_Hailsham]

the only switch i see near the boiler is a fused one, but when i switch it off it switches the controls panel off

and the wires run to the junction box then 2 wires go down under ground.

That sounds like the main switch. You can easily check if you have a multi-meter. If you're not sure, turn the main switch off.

the tank im on about is a small red one at boiler, a red one abt size of a football with a pressure gauge on it, i sometimes have to top this up as the system makes a noise if its below 1 bar

So you have a sealed system boiler then; I thought you meant an open feed tank in the loft.

It will probably be easier to drain the system then. You only need to be below the valve.

You will need to add some inhibitor when you refill. You can get cartridges which can be injected via a radiator bleed screw. Do it, before you refill, at one of the upstairs rads as they will be empty.

how do i test the motor in the mid valve in case its just that that's away

The easiest way is with a multi-meter. But you have to test the whole circuit to make sure that the correct voltage is available to the motor.

See How a mid-position valve works

 

[G1zm0]

Im not sure if its the main switch , ive posted a pic of the switch, junction box ect

to bleed i jlack up arm on float in loft then turn drain cock outside and loosen a rad beled valve?


tryed to upload pictures but it wouldnt let me came up site error

 

[D_Hailsham]

Im not sure if its the main switch , ive posted a pic of the switch, junction box ect

If you are not sure, turn off at the main switch for the house. Don't forget to reset all the clocks and don't open the fridge/freezer door!

to bleed i jlack up arm on float in loft then turn drain cock outside and loosen a rad bleed valve?

I am getting confused! You said that you have a small red tank near the boiler with a pressure gauge. This means you have a sealed system.

Now you are asking about the tank in the loft.

How many open tanks are there in the loft?

If there is only one large one, that has nothing to do with the heating system. It's the cold water supply to the taps and to the hot water cylinder.