Browse Forums General Discussion 1 Mar 07, 2014 6:29 pm Hi All, We moved into our almost complete reno just before Christmas, and one of the things that is bugging me is the HWS. It is an instant model (Bosch, see pic below), but the water takes forever (1-2 minutes) to get hot. In point form, here's what we've looked at or thought about so far: 1. The HWS is located right next to the ensuite, but water in the ensuite takes just as long to get hot as anywhere else. 2. I can hear the HWS "fire" as soon as the hot tap is turned on (I haven't tried this "cold", only after timing how long it takes to get hot). 3. I haven't crawled under the house to look where the pipes go. Photo for reference: Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ I have two questions for the group: 1. What is a normal "acceptable" time before hot water should get hot? 2. How should I approach this with the builder? Thanks in advance for any advice. Cheers, Dim Re: Instant Hot Water System (HWS) - not so instant? 2Mar 07, 2014 8:39 pm This is one of the things I looked at closely during our planning stage as we previously had a Solar HWS with gas boosted on demand system on my 1990s home. The on demand system is not the problem its the lenght of pipe from it to your outlet and water pressure. In new homes they normaly run the plumbing up the wall and inside the roof and back down the wall. At our futherest point (en-suit) in our new home it takes at a guess 20 seconds which would be 15 mtrs (more like 20mtrs of plumbing) as the crow flies and about 10 seconds with it being 3 mtrs but the plumbing would be 5mtrs (laundry). Re: Instant Hot Water System (HWS) - not so instant? 3Mar 08, 2014 9:48 pm That is a bit slow. We have a very similar model Rinnai 24 Infinity that does almost the same thing and has done since we had it installed about ten years ago. Despite the fact they are called "instantaneous gas hot water heaters" they are anything but. They should be called "a bit slower than instant heaters". Ours is just outside the laundry and kitchen and takes 25 seconds to get where hot water is coming out of the tap in either room. The bathroom is about 10 further metres away and it takes about another 15 seconds for it to get there. I'd ask the builder if you can get the plumber to come and have a look at it. I've been to Europe where some of the ones there are in the 10 second range which is about as good as you'll get I think. Stewie Re: Instant Hot Water System (HWS) - not so instant? 4Mar 09, 2014 8:22 am A minute or 2 is a little long. But than you will need to take into account of how your pipes are laid out. The HWS next to ensuite might not be necessary the closest to the tap. Also don't forget the water pressure too. Re: Instant Hot Water System (HWS) - not so instant? 5Mar 09, 2014 9:01 am I understand the timing is the issue for you rather than the wastage of water. But just a suggestion...we've already decided to collect the cold shower and sink water in clean buckets rather than just letting it run down the drain until it gets to the right temperature. We'll be on a rain water tank so don't want to waste any. . .(We might as well put it to some use, in the kettle, for cooking, on the garden etc.) Initially I was shocked to see all my pipes in the roof but apparently this is the plumbing regulation now for when a block has had excavation and fill. Makes it easy to see which is the shorter run too. Why not save the extra water while you wait? 2 mins of running water; I wonder how many litres that adds up to every day on your water bill? Re: Instant Hot Water System (HWS) - not so instant? 6Mar 09, 2014 1:02 pm A logical solution TSC and one I've done myself. I know you can buy cheap diverter flaps for waste pipes that would be a classier solution ( forum member SaveH2O has one in his kitchen ) but I'm unsure how you would do this in a shower. Anyone know or has seen a product like this ? Stewie Hi all, Iām looking for opinions regarding a good LPG instant hot water service. I currently have a small storage tank on an electric heat pump and with our growing… 0 4835 Family of 4. Had 1x 315L Sanden Eco Plus for 4 years. Never ran out of water, even with guests staying. 4 6889 9 19503 |