North Leeds Plumbing & Heating – Home Improvement and DIY Advice

Corrosion is the enemy of the central heating system and using a good proprietary inhibitor in the water is essential to avoid rusting of radiators and other components. It is a simple task to check to see if your central heating system has an inhibitor in the water and whether it is working efficiently.

Firstly take a sample of water from a radiator which is easier than you may think. Find the drain cock used to drain off the system; this is usually at the base of the boiler if it is a floor standing one, or on a radiator if the boiler is wall mounted. You will need a small amount of water in a suitable glass or bowl into which you put a clean bright nail along with a piece of copper, a coin is fine. This is then left for a few days and when checked if the nail has rusted, there is no inhibitor or not enough in the system in which case this should be added, to do this the system has to be drained.

First ensure that the cold water feed to the expansion tank is off either by closing the wheel valve if fitted, or by tying up the arm on the ball valve. Then fit a suitable hose to the drain outlet, open all the radiator valves and wait until no water is seen running from the hose. It is recommended that the system is flushed using a proprietary cleaner added to the expansion tank and run for the heating for a few days. Repeat the drain off procedure and then add a good inhibitor to the tank which should be at a concentration recommended on the pack normally the guide instructions suggest this is calculated by the number of radiators in your heating system. It is worth being generous in the amount used by adding slightly more than the recommendation. The cost of the inhibitor is cheap compared with the price of replacing leaking radiators or a boiler which can happen through corrosion and it will last for years before you have to check the efficiency of this again.