Can I fit my own electric water heater?
Small electric water heaters have become extremely popular over recent years. And that’s not surprising: they are a great way to provide localised hot water to one or more sinks or basins (for example in a utility room or outbuilding) where the alternative is to have a long pipe-run from your main hot water system. Long pipe runs can be both inconvenient (because you have to run the taps for a long time before the hot water finds its way from your boiler to the tap) and inefficient (because after you have turned off the tap, the long pipe-run is full of hot water which then cools down).
And another major factor is that they have become very inexpensive. This of course, is great news, but it also means that the cost of getting a qualified plumber in to fit the unit can be far more than the cost of the unit itself – and that’s always a bit frustrating!
But is it feasible to fit it yourself? Well the answer is yes, but with a few important points to note:
1. Firstly, the unit must be less than 30 litres. If it is 30 litres or more, you must hold the G3 qualification (if you do get a plumber in, make sure he has this qualification, don’t just assume it!).
The reason this rule is in place is that as water heats up, significant pressure can build up inside unvented water heaters. This pressure increase must be dealt with safely, else the heater can literally explode.
2. You must be a confident and competent DIY-er in terms of plumbing. You will need to make connections into your cold water supply, fit various valves and route an overflow pipe.
3. You must also be confident in making electrical connections, because you will need to connect your unit into a spur outlet.
The video below is an excellent summary of what is involved, and although it is for an Ariston unit, the principles apply in exactly the same way for other brands of heater.
As far as we are concerned, the most important point is that you are not tempted to cut corners regarding the need for an expansion vessel or pressure relief capability – these are explained very well in the video.
