Browse Forums General Discussion 1 Mar 24, 2014 1:28 pm Hey. We built a house recently and are currently going through our 6 month fixes. One of our issues is with our instant hot water system. When having a shower in the morning, it takes 30+ seconds before we get any warm water. We've been told this is normal and accepted it. A bit annoying, but manageable. HOWEVER, what also happens is that randomly when showering, I will lose ALL hot water! I then usually turn it up (feel like it recovers quicker) and wait another 30+ seconds before it comes back. This happens on average once every shower. In between, the temperature is holding fine and doesn't fluctuate. We have been told by plumber that this is normal. They attended and turned it up scolding hot and it never lost the temperature. They said we don't shower warm enough for it to be able to hold the temperature. They supposedly also adjusted the pressure, but I don't see any difference (pressure feels very low to me). I find this very hard to believe. No, I don't shower scolding hot, but I shower warm enough that the shower screen is completely fogged up. Surely that is enough? None of us has ever had this issue before, but I suppose everywhere we've lived before has probably had tanks. Would appreciate any help in solving this matter! What is the issue here and is it "normal"? What can we do to fix it? What is the builder obliged to do? They recommended some wireless controller which can "control the temperature of the water regardless of the water flow". Anyone has one of these and can comment? This would be at our expense and even though I don't think it is an acceptable solution for us to invest our own money to _maybe_ fix this issue, I'd be interested in your opinion on this as well. Maybe a compromise can be that they fit this controller for us. http://www.rinnai.com.au/hot-water/cont ... ontroller/ Re: Instant hot water not holding temp - told it's normal?? 2Mar 24, 2014 1:38 pm Can you provide details if which hot water service you are using?? Re: Instant hot water not holding temp - told it's normal?? 3Mar 24, 2014 1:43 pm AussieMark Can you provide details if which hot water service you are using?? Yes of course. I went outside and had a look just now, and it had a big sticker saying "B24", so I assume that's the model number. I can try and find more details if it would help. Brand is Rinnai. We are in a small two story house with the hot water mounted outside downstairs and the showers being upstairs. Re: Instant hot water not holding temp - told it's normal?? 4Mar 24, 2014 4:42 pm I had a similar incident with a client who had trouble with an earlier series Rinnai Infinity 24 and I did a bit of research for her. A few things that may help is to make sure that the heater is getting 4L per minute flow or greater otherwise it won't work. Another is that the 50ºC compliant temperature can be adjusted although some models can't be changed above this even by using a controller. Also some models ( now I'm talking the older models here ) have a series of dip switches that can be adjusted by an "authorised " person to get a higher temperature above the 60º C factory default setting. The authorised person I'd suggest is not a standard plumber but someone like gas HWS repair mechanics or technicians who are familiar or trained to do this. HTH By the way my client worked out that by turning the hot water on maximum ( probably achieving greater than 4L per minute ) and adjusting the cold fixed the problem after the plumber got a Rinnai rep/tech guy to have a look at it. Stewie Re: Instant hot water not holding temp - told it's normal?? 5Mar 24, 2014 5:13 pm Stewie D A few things that may help is to make sure that the heater is getting 4L per minute flow or greater otherwise it won't work. Another is that the 50ºC compliant temperature can be adjusted although some models can't be changed above this even by using a controller. Also some models ( now I'm talking the older models here ) have a series of dip switches that can be adjusted by an "authorised " person to get a higher temperature above the 60º C factory default setting. Sounds like you are suggestion we raise the HWS temperature if I understand you correctly. I'm pretty sure they did this last time, and I feel like it has gotten worse. Also, if we want a higher hot water flow, wouldn't we want to LOWER temperature so that we use more hot water and less cold water to get the required temperature? Re: Instant hot water not holding temp - told it's normal?? 6Mar 24, 2014 6:04 pm I'm no plumber tompab - just giving you suggestions to work with but I think you are correct in that lower HW temp means you need more HW thus increasing the flow. It all depends on your HW unit and what the plumbers have done or haven't as the case may be. As I said, my experience was for an older model and I'm unsure whether Rinnai use the same components as yours. Sometimes it is a case of just getting the right guy to have a look at it. Good luck. Stewie Re: Instant hot water not holding temp - told it's normal?? 7Mar 24, 2014 9:37 pm Hi You need to have the water flowing fast for the heater to keep heating, if the water flow is too slow the heater will cut out and then you get cold water until you turn it on fast enough to fire up the gas again. It's possible that because you have previously been on tank water that you are more careful of the amount of water that you are using and just aren't turning it on hard enough. It's not about how hot the water is it's about how fast it's coming out. Re: Instant hot water not holding temp - told it's normal?? 8Mar 25, 2014 3:59 am I've been using instant hot water for a long time. There are actually 3 situations and as dreamin stated, it is not how hot the water is. The issue is with how fast water is flowing. - If water flow too slow, depends on the type of instant hot water system you will either end up with a constant hot water flow or complete cut off. ie: similar to what you are experiencing. - Water flow at suggested rate (need to check your hot water unit to know), everything just work fine. - Water flow too fast, you will end up with either not hot enough water (if difference between the original temperature and the desired temperature is significant, hence water flowing too fast for hot water unit to handle). If the difference is not that big, there would be no problem. Re: Instant hot water not holding temp - told it's normal?? 9Mar 25, 2014 8:47 am we have one and it does what your experiencing if the flow is too slow. The way we operate it is set the temp to 44ish and pretty much use 'full hot' (I use a little bit of cold as what suits the wife is a bit hot for me). The kids have their bathrroms controller set to 40 and they use full hot (most of our taps are flickmixers). When filling the kitchen sink for dishes, we up the controller to 55 and use that. We find it works really well. Only think I have an issue with is I do B&W photos in my darkroom, and I can't get the tap to run at a low enough temp (20C) for washing film (I use another method that actually saves water anyway) the sun master is the solar heating to "warm" the water in the tank the S26 is your hot water system which will heat the water (25 degrees?) so with both turned on you… 2 13747 I want to build a decking to the drawn shape outlined in black. The problem is how close can I build to the gas hot water unit? Will I be able to build around it and be… 0 20228 DIY, Home Maintenance & Repair Hi, I've got a brand new (2nd hand) Bosch Hydropower 16H tankless hot water heater. Since it was installed I have noticed it leaks a lot. I took the cover off and it looks… 0 24147 |