Electric shower or combi fed shower in a tenanted property?

Hi Tony,

Like you I am not a big fan of electric showers as they always seem a bit weak and temperamental in maintaining a constant temperature. Mixer showers from a hot water tank as long as you have pressure seem far more consistent, but I am not familiar with how they work using Combi boilers.

You can get a great powerful shower via a combo boiler as it's a pressurised system and a good thermostatic mixer will control the temperature issue especially when someone turns a kitchen tap on at the same time.
My personal preference is the combo if for myself but there are extra benefits using electric with a rental property being if the boiler breaks down the tenant still has hot water. So a couple of electric heaters will buy you time to sort the boiler out without the tenant screaming at you.

Thermostatic mixer showers work very well from combi boilers - if installed properly.

I much prefer using the combi boiler shower I have because it seems cheaper on fuel than electric showers. It is also quicker to heat up than the electric showers I have used. Ditto for maintaining consistent temperatures. (I am one person in a one bed property).

Separately, whichever you decide on, don't try to save money on doing it properly. My new boiler was £2400 (thermostatic shower already in place) - I don't know how that compares to a quality job on an electric shower. Which? magazine has some very informative articles discussing the two over the last 3/4 years. These are searchable.

I always fit electric showers (at least 8.5kw for a resonable flow) because if the boiler breaks down the tenant still has hot water so its not an emergency. A combi fed shower may be a bit cheaper to run for the tenants but its totally dependant on the boiler. Also if you have a low water pressure and/or small combi boiler eg 24kw in a flat a combi fed shower won't have a particularly good flow. Apart from the wiring which you only do once the costs aren't very different, in fact the electric shower is often cheaper than a thermostatic one.

the only way to go is a combi and good shower mixer, everything in life breaks down.

The more tenants under one roof, the greater the need to have a hot water tank (such as a Megaflo or other generic versions of same). This is because combi’s generally don’t have enough grunt to deal with three hot taps open at once. Some can deal with two taps at once, most are happiest with just one. Megaflos are expensive at £3-5k and they’re bulky, but for a six-person HMO like mine they are indispensable. I wasted a lot of money before I found that out!

Electric shower all the way, if the boiler breaks down then the tenant has no hot water. At least with an electric shower they still have hot water so the tenant isn’t on the phone ever 2 minutes for an update on the boiler part that has been ordered!! The only down side is the initial cost to get one installed.

When I first moved into my current property the shower was fed from the hot water tank and the pressure was desperately weak and also scolding hot.
I changed the whole set up and installed a combi-boiler which works great, so much so I eventually had to fit a flow restrictor on the shower house.

A friend of mine recently had the same dilemma (for his own use he's not a landlord). He decided to have a shower powered from his existing combi. The flow rate turned out much better than an electric one. As he needed the shower over his bath it was very cheap to install. He purchased a bath mixer tap with integral shower attachment from Screwfix for around £60 (the kind of thing you see in a hotel bathroom with a little pull up plunger device to alter the water flow up the shower cord) and got a plumber to fit the new mixer/shower tap for £50. A pole and curtain was £30 so total cost around £150.

In my experience the biggest problem for tenants is when they can't have a shower because it's broken for whatever reason. I always fit both, then you havn't got quite the same emergency when one goes.