Combi + Delayed Hot Water Options?

[capricious71]

Hi,

just had a Baxi Duotec 28 installed in a bungalow. Seems fine.

The distance between the boiler in the kitchen and and the bathroom is about 20 feet, though I guess the pipes go up into the loft, etc. It takes about 30-40 seconds and a lot of water until it starts to get hot. I supposed there's cold water in the pipe as well.

I just wondered what the best course of action would be to give more "instant" hot water. I've seen these tankless water heaters that can go under a sink (maybe in a vanity unit). Plumber says they're ok but was interested in other points of view.

Thanks,
Ed.

 

[ShaunCorbs]

No waste of time

Does your boiler have a pre heat option?

 

[capricious71]

I've not seen that option in the instructions.

 

[capricious71]

Are tankless heaters really a waste of time? I've seen good reviews.

 

[ShaunCorbs]

Are tankless heaters really a waste of time? I've seen good reviews.

When you have a combi yes

The biggest time delay is the boiler starting and heating the water 10-20 seconds

Pre heat keeps the water hot so as soon as the tap is open you should have within 10-15 seconds hot water, your going to have to draw the cold water out of the hot pipe first

Do you know if the pipes are insulted in the loft

 

[townfanjon]

Yes sorry its the typical combi problem , hopefully the pipes are insulated, it maybe worth getting a thicker insulation

 

[Nwalky]

Try not opening the tap fully, if you open it say a quarter of a turn then your giving the boiler a chance to heat the water. If you open it fully then the water is flowing through the boiler too quickly and is not able to heat it sufficiently.

This is one of the main complaints with combis, mainly because people say they cant run a warm bath, but if you reduce the flow rate at the tap (open halfway/quarter turn) then you will find that the the water will start to heat well (slowly.. but toasted)

Like ShaunCorbs said, if you look at the boiler instructions then it will tell you how to put it on a preheat mode, meaning that when you open the tap the water should be at least be warm instantly rather than waiting for longer periods 🙂

 

[Old Account]

Is there it something like a combi smart/ flowsaver ... I've installed them ones and was quite impressed. It helps to reduce the wastage of water ...

 

[king of pipes]

This is what you mean Ronny combi save cost about £50 but can save that and more per year . cheers kop

 

[Old Account]

This is what you mean Ronny combi save cost about £50 but can save that and more per year . cheers kop

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View attachment 31882

Thanks KOP.

To men. I just seen it once here posted by an older but loving person masood !!!

 

[ShaunCorbs]

Seen a lot fail after a few years

 

[Old Account]

Seen a lot fail after a few years

Really?
So for now I am lucky. would you not recommend installing them ?

 

[ShaunCorbs]

Really?
So for now I am lucky. would you not recommend installing them ?

I wouldn't no seen too many people having problems 2-5 years down the line with the sensing device sticking

 

[king of pipes]

The op asked for options shaun thats one that is proven to work the duo tec has no pre heat . Ariston unvented under sink water heater is another if you want point of use but only 10 litres so abit limited , at some point everything fails that is what keeps us in bissness i wouldnt have a problem fitting one . cheers kop

 

[ShaunCorbs]

The op asked for options shaun thats one that is proven to work the duo tec has no pre heat . Ariston unvented under sink water heater is another if you want point of use but only 10 litres so abit limited , at some point everything fails that is what keeps us in bissness i wouldnt have a problem fitting one . cheers kop

Could you fit a src on a duo ?

 

[king of pipes]

I suppose you could never done it power supply is usually the problem.

 

[capricious71]

Thanks for all the replies. Something I was thinking of asking is about the pipe diameter.
The hot water pipe going into the bathroom (presumably branching off to basin and bath) is 22mm. As far as I know it should be 15mm for that pipe coming out of the boiler.

That means there's more than twice as much cooled down water in the pipe before it gets flushed out by the hot water (Thinking about the volume of a cylinder being V=πr2 h !)

So would changing that pipe run to the bathroom help?

 

[king of pipes]

It would save on water as you say . kop