On my last blog, I talked about isolating the water if it is needed to deal with a problem, or for general maintenance or changes. I discussed how important it is to have a working stopcock.

If you have a combi boiler or an unvented cylinder, the water main is connected directly to the boiler and the cylinder so when the main stopcock is closed, all the water is turned off.

On older systems, and some new systems, there is a large roof header tank which stores cold water to feed the copper cylinder that heats the water. This is generally in the airing cupboard. Should there be a leak on the hot water pipework, or if we need to work on this pipework you, or we, will need to turn off the water feed from the roof header tank.

We very often find that these isolation valves do not work. They seize up due to a combination of age and disuse. We would strongly suggest that you find this valve so that you know where it is, and that you try it to see if it will work. To find the valve, the water from the header tank is fed into the bottom of the cylinder and this pipe will go up to the loft. Somewhere on this pipe there will be an isolation valve, often a brass valve with a red round handle. As with the external stop cock, try it to see whether it works and if you have any problems we are happy to help – it could be in our interest if we need to turn off the hot water in a hurry!