Combi boiler and water wastage

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Emmachuck
Lively Laner
Posts: 419
Joined: 02 Mar 2011, 20:24

Combi boiler and water wastage

Post by Emmachuck »

When we moved into our house about five years ago, we had a new condensing combi-boiler fitted. It has been serviced every year, so presumably is running at maximum efficiency. However, due (in part, we think) to some creative pipework around the house and old extension, we have a problem that is increasingly bothering me: a) as I don't like wasting water anyway and b) as we are on a water meter and prices are set to rise over summer. When we use the hot water taps, it takes a very long time for the water to heat up (at least two washing-up bowls full in the kitchen, two or three sinks full in the bathroom). I hate just running all that water down the sink, but if you stop to empty the bowls into a butt, onto the plants etc., you are back to square one. Does anyone know of any kind of "diverter" system or anything we can do relatively simply and cheaply to do something with this water (other than waste electricity by boiling a kettle every time we need hot water instead)?

Thanks for listening to my rant!

Emma
Steve the Gas

Re: Combi boiler and water wastage

Post by Steve the Gas »

I will sort you out with this later ............. if I could, as I have gotta go in a min, that nasty four letter word needs attending to.

Many things can be done but I have to understand your existing system so, could you list the set up:

Boiler - make/model?
Pipework what diameter thruout?
Boiler how many KW?

Talk later.... )t'
Mrs B

Re: Combi boiler and water wastage

Post by Mrs B »

Oooh good thread my combi boiler is the same, it took us ages to cotton on to the problem.

In my case we know it is the fact the bathrooms are so far from the boiler, we just wash hands in cold water instead. The utility sink is next to the boiler so we use that one for washing up and that is pretty quick.
Emmachuck
Lively Laner
Posts: 419
Joined: 02 Mar 2011, 20:24

Re: Combi boiler and water wastage

Post by Emmachuck »

Hello again,

the boiler is a Worcester Bosch Greenstar 25Si (or 30Si-can't see anything on the boiler or paperwork to indicate which one!). I think the 25 and 30 refer to the KW. The house is a three bed link-detatched running ten radiators. The fat pipes coming out of the boiler are about 2 cm diam. and the thin pipes are about 1 cm diam. Can't see much of the pipework in the house, as it is all boxed in, but it is definitely not the micro-bore, which I know some more modern houses have. The pipework under the sink is about 1 cm diam.

Sorry, that's not more helpful-will have a look for more info when I have taken DS to school! :-D

Emma
Steve the Gas

Re: Combi boiler and water wastage

Post by Steve the Gas »

It will be 24 or 30 KW.

Just like Mrs B - how far is the boiler away from hot water outlets that have a problem?
Also if piped in 22mm pipe for the hot- tooo big for a combi, need to be 15mm really for optimum performance.
When drawing off hot water make the flow slower - it will get hotter quicker iyswim. )t'

So initially is the HW side piped in 15 or 22, if it is 22mm - changing this to 15mm will improve the performance.
Diverter valves on these can be a problem too, a sod to change.
Emmachuck
Lively Laner
Posts: 419
Joined: 02 Mar 2011, 20:24

Re: Combi boiler and water wastage

Post by Emmachuck »

Hi Steve,

thanks very much for your reply. The hot water pipe is 15 mm. The boiler is in the garage on the wall which is adjoined to the house, so a fair distance away from all the taps. The problem is universal to all the hot water taps except the one in the utility sink which backs directly onto the garage and which we had put in- some sort of creative piping by the plumber maybe?

We have tried running the water slowly, but that means the boiler heating doesn't kick in at all. The water seems to have to be going at a fair rate to get the heating started and then we can turn it down to increase the temperature. There is not a problem with the final temperature when eventually the water heats up-it's just that we have to lose enough water to create our own reservoir before we get to that point!

Not really sure if we can do anything to resolve the problem, but it really is literally a case of money down the drain. {cry}

Emma
Steve the Gas

Re: Combi boiler and water wastage

Post by Steve the Gas »

I would ask a diff plumber to price re- routing the hot and cold or is that totally not gonna help?
Are you sure it's 15mm on the hot thruout or did the original bloke utilise some existing pipes - so all floor boards stayed down?

When hot water is drawn from a combi the heating side CH, is tmeporarily stopped by the diverter valve. It could be this valve not being sensitive enuff.
Again a good boiler person by word of mouth may help you - at a cost, but that is relative to the cost of water wasted.
Some boilers mis- behave if you have a dripping hot tap- the Potti Puma springs to mind.
Emmachuck
Lively Laner
Posts: 419
Joined: 02 Mar 2011, 20:24

Re: Combi boiler and water wastage

Post by Emmachuck »

Thanks again Steve. When the new bolier went in, a lot of the floorboards did come up, and some radiators were moved. I know a lot of the piping was replaced, but not sure that it all was. I don't think having the pipework redone is an option ATM from the expense and the disruption point of view.

Good suggestion about asking another heating engineer his thoughts on the boiler. One of my sisters has a very good "man"!-very expensive, hard to get hold of, but apparently very good (yes, still talking heating engineer!!). I will mention about the possibility of an insensitive valve! Not got any drippy taps (although did manage to accidentally screw the bathroom sink tap round the wrong way when I was cleaning it the other day!).

Failing that, I will have to rig up some sort of hosepipe affair out of the window every time I use the hot taps )j; . Thanks again.

Emma
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