Want the Best Electric Combi Boiler for Your Tiny House?


The British have been keeping a secret…

But now the jig is up, because Tiny House Blog is on to them!

What’s the big deal?

Combination boilers! (Combi for short.)


Best Combi Boilers for Tiny Houses:

Best Gas Model:

Westinghouse Condensing Combination Boiler

Price: $1,957

– Including heat-harvesting gas condensing capability
– Digital temperature control
– Comes with a warranty
– Fairly low flow rate, at 3.2 gallons per minute
– Water pressure in the home is dependent on the pressure of your local water main
– Volatile fuel prices

Best Electric Model:

ThermaFlow TH9-210U MRK 2

Price: £2,249.52 ($3,118.51)

– Appropriately sized for tiny houses
– System can be set to automatically use off-peak electricity (company claims as much as 40% savings)
– Reduced fuel price volatility
– Compatible with renewable energy sources
– Currently higher operating costs
– Must be ordered from the UK
– May be difficult to find a contractor competent to install it in your home


Now, you may be asking what the heck I’m talking about…

A combination boiler is a marvelous new technology that allows water to be heated on demand directly from the water main and then routed to multiple appliances within the home for different purposes, like showering, dish/clothes washing and radiant subfloor heating.

The principal advantage is space savings, because the technology eliminates the need for bulky equipment like a cold water storage tank or hot water storage cylinder. (That means no frozen pipes, northerners!)

Additionally, you’ll have unlimited access to hot water at high pressure – perfect for a relaxing shower, or hosing off the kids before they come back inside your tiny house after playing in the garden. The only drawback is that it might take a few seconds for your water to reach the desired temperature.

Combination boilers primarily come in two flavors: gas and electric. For all intents and purposes, both approaches are equal in dignity, so choose the one that fits best within your overall energy supply plans. You can also get similar mechanisms that are wood-fueled, or designed to operate with a solar-heated roof-mounted storage tank.

If reducing your ecological impact is a priority, an electric model supplied with renewable energy technology could be your best bet. By taking the hot water cylinder and electrical pump out of the equation, an electric combi boiler could save as much as 30% on your energy consumption related to water heating compared to conventional electrically powered appliances. Electric models are also silent.

In terms of overall energy costs, a gas model is most likely to result in the most financial savings for you in the short term. Among gas models, a condensing boiler is the one you want. It’s the same thing as a combi, with the added capability of squeezing the heat out of burned fuel before flue gasses are vented outside. This will lower your gas bill as much as possible, while ensuring your boiler burns cleanly. For more energy saving tips, check out this awesome video.

Combi boiler technology means that you easily route hot water, on demand, to different appliances in your house. By running hot water through a concrete or earthen floor slab, for instance, you can easily heat your home in winter, and then turn around and use that same water for your domestic cleaning needs. In combination with intelligent, passive solar design strategies, you could stay warm all winter without having to install a wood-fired stove. (Leaving you with tons of room for that burgeoning shoe collection.) If you’re interested in learning more about passive solar design, take a peek at this article.

A brand new combi boiler will likely run you between $2,000 and $5,000. A family of four with a 50-gallon electric model, for example, will use somewhere in the range of 14,000 kWh per annum. At an average cost of $0.12/kWh in the USA, that comes to just under $1700 a year for electricity. Not bad, considering that you’ll be meeting all of your domestic water needs, on top of heating your house in winter, (and I wouldn’t be surprised if a typical tiny house owner would use far less energy than that).

Gas, on the other hand, would likely cost about a third of that to operate on an annual basis, but those cost savings are largely due to a drastic reduction of natural gas prices in recent years. In 2010, the costs would have been comparable for gas and electric, and when fuel prices go back up in the next decade you will likely wind up paying more than someone with a similarly sized electrical model.

If you want to learn more about what it’s like living in a tiny house, consider planning a visit to Dancing Rabbit Eco-village. We have more than a dozen small homes in one spot, and you’ll get to see all the different tips and tricks we use to live the lifestyles of our dreams for less money, and with a lower ecological impact.  (Of course, you can always do things the old fashioned way…)

1 thought on “Want the Best Electric Combi Boiler for Your Tiny House?”

  1. Not going to lie, I didn’t know that a boiler was a piece of technology that allows water to be heated on demand directly from the water main and them routed to different parts of the home. I can see how they would help save money since, like you mention, they replace bulky equipment such as water tanks. I’ll have to really look into this boiler system and see about putting one in my home.


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