Instant water heater

It's just the age-to-fill issue. I've got a 27kW combi, and a small bath, and that's just about bearable. Even the 12kW version of this electric heater would take over twice as long as my boiler. I don't know what the rate of heat loss from a large shallow body of water open to the air is, but over the time it would take to fill you'd be struggling to get it beyond tepid.

We used to have a Mains Severn (?) and it was very efficient at filling a bath with hotter water than needed.

The one you feature does say, "Allows you to supply up to 2 basins or 1 basin & 1 shower with instant hot water" which isn't suitable for a bath :-)

Mary

I really don't know: I've been happily using the 9.5-kW version for DHW for eleven years. It takes me about 17 minutes to run a bath, but I do fit in quite snugly! I have forgotten a couple of times and run it for over 40 mins, without problem. Martin.

Anglia Water suggests that an average bath water usage is 80l so it would take around 20minutes to fill. The water final water temperature needs to be around 38C to feel comfortable for a toddler so for an adult it probably needs to be a bit hotter.

/About/ 17 minutes? Have you no stopwatch?

That's good info too, thanks, looks like the idea is a runner.

Is it to supplement a combi?

Main (now part of Baxi/Potterton) produced a whole range of these over many years. I inherited a Main Medina when I bought a house which eventually wrecked itself about 8 years ago (see humour pages of the FAQ) and I replaced it with the then current one with thermostatic control, Main Medway...

Sorry, no, nor a thermometer... Timed it tonight at 19 mins. Perfect! Just below the overflow with me in, with no additional cold required. (Incoming water must be getting colder. Next stage is to turn the tap down slightly when it's really cold.)

Forgot to mention that the input pipe is plastic, allowing some expansion? and output pipe is microbore, replacing some truly grotty old lead plumbing and giving the water chance to reach the tap before it's gone cold! Cable is 6mm**2, part clipped direct, part plastered over and gets barely warm. The lights dim a bit, but they also do that throughout the evening when anyone else on our street on this phase uses an electric shower... The house had a pre-WWII cylinder with tank just above, all in the back bedroom, heated (well, just the top 1/3) by (1950s?) immersion, the old coal back-boiler being unusable because of the gas fire and being in a smokeless zone. The Powerstream was originally installed to give a shower and run the bathroom handbasin, but once I'd found that the bath could be filled OK using the shower, and the temperature could be increased enough to do washing-up by turning the tap down once the unit had fired up, the old junk was scrapped. I don't know why they aren't more popular. Particularly now more powerful ones are available. (I would have liked a gas multipoint, but there's really nowhere convenient to install one. Or even a combi-boiler and central heating one day, but I like my old gas fires and British Gas keep offering me central heating service contracts which would cost more than my energy bills! This thing has cost nothing in maintenance for 11 years.)

Ours was, in fact the present boiler is too, fitted to the kitchen outside wall, high enough not to be noticed but serviceable from a step ladder. I thought they always had to be on the floor but Spouse said no and put it up there.

There's nothing to stop you having a boiler AND gas fires, we do.

Mary

In message , Martin Crossley writes

Yes, I had one like that, when I took it out turned out one reason was that it was about 50% full of limescale, in big chunks that had fallen off the walls of the cylinder over the years

In message , Doctor Drivel writes

Yep

How long have you got?

NT

The "Main" ones could only go on a wall -- they hang from the through-the-wall balanced flue. Main actually went to some effort to ensure the newer ones could be hung from the flues of the earlier models, which made replacement much easier as you didn't have to change the flue.

I kept 2 out of 3 of my gas fires and the multipoint when I put the boiler and central heating in. The boiler only does the central heating, and the multipoint continues to do the hot water. The gas fires are decorative in one case, and a backup in the other. (The 3rd one was at end of it's life and thus went.)

Well, having finally got someone to quote and date it maybe goes to the back burner .... once again.

That's OK, stacks of them in the loft, if I shovel them out it's two jobs done in one.

I've no idea about 'Main' brands.

We did the same. We retired the multipoint when we installed solar water heating, the new boiler is for ch everywhere except sitting and dining rooms, and boost to hot water on cold and overcast days.

There are usually several solutions to individual circumstances :-)

Mary

You could have kept the multi-point (see makers first, as some don't like hot water acting on the diaphragms.) and had solar hot water feed the multi-point. But you need a high pressure storage cylinder (unvented), or use a thermal store at low pressure using a plate heat exchanger. Then electric backup can be fitted in the cylinder. All with space permitting of course.

When the multi-point packs in get a Rinnai multi-point. But fit a flow switch on the cold mains supply to it, switching out the boiler when DHW is called to save overloading the meter. The flow rate is world away from a Main with top reliability. You can have a remote control in the bath or shower and raise or lower the temperature of the water suit.