Instantaneous electric water heater enquiry

[phargreaves]

Last year I spent many thousands on a new condensing boiler and new pipework to old radiators (the old space heating system was a 1 pipe system). At the same time the new pressurised (megaflow) cylinder was connected to the bathrooms and kitchen and 2 bathrooms were completely re-fitted. Although I had made it clear that I did not want a long time delay in drawing off hot water from taps in bathrooms and kitchen (thinking the plumbers would install a secondary pumped h.w. circuit) in the end that's what I got. They said it would have been too difficult and I have to say they may be right because of sundry access problems that I don't need to go into.

I'm not going back to those plumbers as they took forever and never turned up when they said they would.

Now I'm thinking of fitting an instantaneous water heater to heat the kitchen sink water (otherwise it takes about 2 minutes to come through from the Megaflow). The water pressure is good - an accumulator has been installed.

Looking on the internet, I see something called a Redring unvented water heater, 12 kw, which is said to be the highest rated of its type in the UK. The site also says it is for fitting on the cold water supply.

My question (at long last) is, can this heater be fitted on the hot water supply, so that when it is used, if hot water is coming through (eventually) from the Megaflow, it runs through the unit which doesn't have to use energy to heat it again. But if the water is cold (that's for the first couple of minutes) the electric water heater works instantly.

Any bright ideas?

Best wishes,
Paul

 

[crockett]

Paul there's no point in fitting that type of heater, or in fact any type of water heater, to the hot supply. These are designed to have an incoming cold supply only, so I'm not sure what you hope to achieve by doing this.

 

[phargreaves]

I was hoping to save energy; if several attempts are made to draw hot water, the supply from the megaflow eventually gets through, so there is no need to re-heat the water. If the thermostat in the electric heater picks up the fact that the water is already hot, presumably the electric heater doesn't bother attempting to heat it up again.

 

[Agile]

Did your plumber leave the hot supply pipes in 22 mm?

The reason we cannot always get to you when we hope to is because we are helping other customers!

We are not just sitting in the pub! ( Well most of us anyway! )

Tony

 

[kevplumb]

whats this your own private messaging service

 

[crockett]

As long as the hot water reaches the outlets within 1 or 2 minutes (!) this is fine. I would guess that you have long runs in your house. Unfortunately This is a design fault, and unless you rip flooring up to run a secondary line, or as you have said install a second system of heating to these problem areas, you will have to put up with it !! I take it also, that you have a large property ?

 

[phargreaves]

Tony,
No, the hot and cold supplies reduce down to 15mm for a long leg.
And, by the way, I am not unsympathetic when jobs take longer than estimated and I don't care where anybody is sitting when they are not at my place. But I become less then happy if three months is taken to do a job confidently estimated at three weeks and little attempt is made to communicate properly and it's the middle of winter and I have no heating.

Did your plumber leave the hot supply pipes in 22 mm?

The reason we cannot always get to you when we hope to is because we are helping other customers!

We are not just sitting in the pub! ( Well most of us anyway! )

Tony

 

[phargreaves]

No, it's not fine. 2 minutes waiting for hot water is a lot of cold litres down the drain.
My question is about fitting an electric instantaneous heater to the hot supply. Why not?

As long as the hot water reaches the outlets within 1 or 2 minutes (!) this is fine. I would guess that you have long runs in your house. Unfortunately This is a design fault, and unless you rip flooring up to run a secondary line, or as you have said install a second system of heating to these problem areas, you will have to put up with it !! I take it also, that you have a large property ?

 

[crockett]

There is nothing to stop you fitting this heater, it's just not the correct way to do it!! It doesn't matter whether fitting a secondary would have been a hassle, it should have been fitted, then you wouldn't be having this discussion I would advise you, if you are going down the heater route, to fit it to the cold supply. You didn't mention how long a run you had from the megaflo to the problem outlet ? Also, the plumbers should have run the pipe in 22mm, reducing if needed at the outlets.

 

[dormermike]

No, it's not fine. 2 minutes waiting for hot water is a lot of cold litres down the drain.
My question is about fitting an electric instantaneous heater to the hot supply. Why not?

As long as the hot water reaches the outlets within 1 or 2 minutes (!) this is fine. I would guess that you have long runs in your house. Unfortunately This is a design fault, and unless you rip flooring up to run a secondary line, or as you have said install a second system of heating to these problem areas, you will have to put up with it !! I take it also, that you have a large property ?

Phil did you fit it, how did you get on? I am considering same. Thanks.