combi boiler

[Royallen111]

can anyone tell me how to get constant hot water out of a combi because i'm thinking of throwing mine out of the window!

[John Rumm]

Make and model?

Define "not constant"?

[someone]

I have a similar problem with my 3 month old Worcester Bosch Heatslave 20/25 I get about 2 Minutes of lovely hot water then it goes cold I then have to turn the hot water off for about 30 seconds and then I have hot water again.

[tarquinlinbin]

Nothing is truly instant, not even light. If you have high water demands or find your existing combi frustrating you could either- fit a newer more capable bloier or fit a hot water cylinder and have it heated by the combi,then you'll have lashings of high flow hot water just like the old days BC (before combis !!)

joe

[Fred]

In my experience, that's coming from the hw flow that you are actually using being too low to trigger the burner. In my case, the less hot water I want to draw the more likely it is that the burner goes off. I need to open my tap at least halfway to get constant hw. It sucks because it forces you to change your habits because of the combi (e.g. doing the dishes under a constant, but small flow of hw - I know it's not energy efficient, but I thought that I could decide how to do my dishes, yet it's the combi that has taken over).

The 30s delay, in my case, allows the built in 3l tank to refill and heat up again, mine is a WB 40 Greenstar Plus.

Fred

[John Rumm]

It seems different combis handle this situation in different ways. I did an experiment with my Ideal Isar the other day, doing just what you described i.e. running a very slow trickel of water. In fact I was actully quite impressed with how well in handled it. On turning on the tap the boiler fired up, but then shut down after 20 secs or so. It then used its (small) internal store to supply water for a couple of mins before ligting the burner again for approx 15 to 20 secs. All though this it maintained a very constant output temperature. I seemed as if it could carry on supplying water like this on an ongiong basis if required.