I'm in the process of building a small cabin in which to live in during the self build of the main house. I'm wondering about hot water options and wondered if anyone had any advice?

The cabin has one bedroom, a bath room and a kitchen / living space. I had in mind to use an electric 10kw shower, but how would you supply hot water to the kitchen and bathroom sinks?

You're going to need a point of use heater or use a kettle or carry basins of water from your shower cubicle to your sink. But if you think you can get away with the latter 2 given the time you expect to be in the cabin I suggest you imagine being in there 2 or 3 times longer and fork out for the ugly little boiler. A further choice is an externally mounted LPG instant water heater.

The static caravan I'm in has an “instant” LPG hot water heater for kitchen, bathroom basin and shower. It works OK though the flow rate is not great.

Still, I was glad to have hot water during a 36 hour power cut last year so there's a lot to be said for having something non-electric.

I scare quoted “instant” above as the one fault with it that annoys me is that it takes quite a lot of water flow to light it so, even if it's run hot only a minute or so ago, it'll send a significant quantity of cold through before it runs hot again. Wastes a significant amount of water for rinsing after shaving and so on. The igniter runs off a pair of D cells. I replaced those and it did speed up a bit but it's still irritating.

It's in a cupboard which is well ventilated. Externally mounted would be good to avoid that as, with the ventilation and the relatively small amount of use, the spare heat from the thing doesn't contribute to space heating.

Just curious, but how do the externally mounted heaters deal with freeze protection?

Having tried both

I recommend Kettle every time

better still 2 with similar bases strategically placed

You will be surprised how little hot water you actually need

Posted By: Gotanewlifeof course LPG needs well low temps to freeze....something you will be familiar with Ed but I am not

However, it doesn't need such low temperatures to make a small amount of water freeze in the regulator. I think it's condensation from the atmosphere on the outside of the bellows or (whatever's in there) rather than WV in the LPG which freezes. The (external, of course) LPG tank on my caravan is on the west side so doesn't get any sun until later in the day so can stay below 0 °C for days on end. That's combined with the cooling effect of the expansion, of course. I had the regulator freeze up a few times which was irritating, particularly first thing in the morning before getting dressed. Wrapping it in some insulation seemed to help a bit.

I was on the point of putting a resistor directly across some 60 W amorphous PV panels I have under the insulation when my landlord came by with a new regulator he'd got with a small weep hole in the bottom to allow any condensation to run out. Has worked fine for two not-particularly-cold winters.

BTW, one tall LPG cylinder (57 kg?, costs about £70, I think) lasts me about a year for all my hot water other than that I top up the temperature of washing-up water with a drop from the kettle.

Posted By: Ed DaviesWastes a significant amount of water for rinsing after shaving

Better to use cold to close up the pores

Posted By: MeJust curious, but how do the externally mounted heaters deal with freeze protection?

Anybody? Despite GoNL's jokes about LPG freezing and my comments about LPG regulators icing up it'd still be interesting to know how these things are protected against freezing water splitting their heat exchangers, etc. Do they just run for a minute or two every so often when it's cold or are they split with an antifreeze-filled loop or what?

Interested as it's an idea for a fall-back fall-back if I find getting enough DHW in my off-grid house is a real problem. Would likely only be used for a few weeks a year so it'd be bad news if they used more gas just doing freeze protection the rest of the time.