Water Heaters...

Our water heater is a 300 litre Sauter vertical cylinder mounted on the floor. For some time now the safety valve has been drip drip dripping, wasting water. We have no idea how old the unit is and also we wanted to know how much calcium had collected on the heating element and the general internal condition, especially since we installed the water softener last July.

We purchased a new safety valve at Leroy Merlin last week and were ready to go... So today, after our guests had left on their trip back to the UK, having used a lot of the hot water showering, it was time for a drain down.

We piped the 300 litres of water directly to our well, so they were not totally wasted. In order to get the water to flow out, the union on top of the cylinder had to be opened. (basic physics, opening the taps did not allow sufficient air in; in fact, none at all. Which proved useful later...)

The old safety valve was removed and replaced with the new.

The main three phase heating element was electrically disconnected and the six securing bolts carefully removed, revealing  the element tube with plenty of fairly loose calcium...

This was scrapped off the tube which showed signs of pitting...

With Elizabeth's help (small hands) the bottom of inside of the cylinder was cleaned of loose calcium...

The element was replaced and the cylinder filled with water. Checking for leaks it appeared OK... Until that is, it was full and the water pressure of 4 bars applied.

A small leak developed where the new safety valve screwed into the T connector. I had not wrapped sufficient PTFE tape on the threads... always a weak point in my opinion.

My first thought was a full drain down BUT with all the water turned off no water came out of the drain as no air could get in the cylinder. So, hoping my physics would hold up I removed the valve with the cylinder still full of 300 litres of water...

No problem! nothing came out of the half inch hole. I wrapped the threads again with a vast amount of PTFE tape, replaced it and this time no leaks... YES another success...

So if you have a similar problem with a safety valve leaking, to replace it you do not need to drain down... Saves time and water...