Installed Titan tankless hot water heater recently and all is well, with the exception that the washing machine water starts hot then gets cold and will not heat back up.
I even turned off the cold water valve at the washing machine and get the same result. What could it be and what should I do?
Thanks
Installed Titan tankless hot water heater recently and all is well, with the exception that the washing machine water starts hot then gets cold and will not heat back up.
I even turned off the cold water valve at the washing machine and get the same result. What could it be and what should I do?
Thanks
Tankless probably has a minimum flow rate,,if the min flow is'nt maintained the heat shuts down,,it sounds like You may be right close to drawing that rate at the wash machine..Is the hot supply valve at the machine all the way open? Dean
Well if everything else is working properly then it has to be the flow is to low to trigger the heater to come on. Have you checked the screen on the inlet of the washer? There might be enough crap in there to cut down on the flow? I run the water in the sink to get my tankless heater going and hot water in the lines while I'm loding the washing machine.
Good luck, Rich
To check minimum flow while running washer turn on other faucet fully, if water then heats its a minimum flow problem.
Check the capacity of the heating unit at a given temperature rise. The figure is fairly low. We do not install them for potable water unless they are aware of the limitations of them, or are willing to install the proper sized unit
The GPM is also rated at a maximum inlet temp. Also a consideration one has to take into account.
I suspect your water heater is too small for your house. I would have the plumber who designed and installed it replace it with the properly sized unit. There is nothing wrong with the water heater.
Another way of operation is to add a storage unit, with a recirc line. In that scenario you would pretty much have unlimited hot water. With out much increase in fuel costs
Yes, replying to 14 year old thread. But info is still relevant, so... I have a 9GPM Rinnai gas tankless and it's terrible for day-to-day use. I'm sorry for your experience but it is typical. An uninterrupted single call for hot water (such as for one shower running or one tub filling) will work fine (if the unit is vented properly and correctly installed for pressure and water flow requirements, mine was not either one originally.) That's where the convenience ends IMO. You can have one continuous call for hot water plus other demands entering and leaving the stream will cause fluxuating temperatures as the unit attempts to adjust to the demand. The worst is for any call for water to start and stop, such as my high efficiency washing machine and dishwasher. The call for hot water from these is brief and stops for a few seconds, then repeats (spurt, mix, spurt, mix, spurt, mix, style of hot water draw). Each time the tankless turns off, cold water will flow by the burners for a few seconds until the burners have it heated up, since there is no reserve tank of hot water to send while waiting. This is called the "cold water sandwich" as it appears inbetween the warm water still in the pipes and when the newly made hot water starts arriving.
We did not want a recirculation pump (which keeps the water hotter) for a number of reasons, so we have learned to live with this tankless by 1) Never using hot water unless we're ready to use a lot of it (e.g. wash hands in cold water), 2) batch/sequence all our hot water usage so the unit runs continually during the time hot water is required. It will still heat up/down according to demand but at least most water will be around 120 (we have ours set to produce 140 degree water). Hope our experience helps someone.
Interesting, I had never heard about that disadvantage, but it makes sense. And don't forget the high install cost if you're switching from tank type. A whole house unit requires a lot of gas and the run from the meter may need to be resized. Some even need new meter service. And for what? The total gas bill here with a tank type is ~20 a month. That includes heating water and some occasional gas grilling outdoors. So how much would a tankless improve that? The main savings is no standby loss that a tank has. But with a total bill of $20, how much can that be and how long would it take to recover the much higher cost of a tankless? BTW, that $20 is with the most basic tank type, ie not power vented. If you go to a power vent type, that would reduce the standby loss because there isn't an open vent path up the middle of the tank all the time.
I'd not have one from my experience. Over a year I spend 4 or 5 weeks at a friend's vacation house and she has a tankless heater. Most times it is OK but you have to run a lot of water to get it hot even if you need a little. If you don't take a shower hot enough it will go cold.
Since the home is unoccupied for weeks at a time it seems to make sense but in reality, for normal use it sucks.
That's odd. They fire as soon as flow starts, so you'd think that water exiting it would be up to temperature very quickly. I'd expect it to be almost the same as a tank type from that standpoint, just a little behind. I would expect the wait for hot water to be governed almost totally by the length of pipe.
If you don't take a shower hot enough it will go cold.
That's what I've always said too, that they could be a good fit for vacation homes. In that situation, if it's a beach house, ski house, especially a rental, it also provides unlimited hot water when everyone wants to shower around the same time.
To clarify, the length of the pipe is a factor but if you want just a trickle, it will not set off the flow sensor to start the burner.
In the morning I'd turn the hot water full on to get the heat going and then reduce the flow to what is needed and blend in cold water to get the desired temperature. If the flow goes too low, the burner shuts off.
I don't know if it can be adjusted. Not my house so I don't tinker with it.
I use gas for hot water, dryer, cooking on the range or the grill. My gas use runs $10 to $12 a month. No way to justify a change.
My BIL ended up with 3 propane fired units for that reason (3 bathrooms and the kitchen) but the reality was there was only 2 of them and then just one. The wait for hot water was about what you expect if you don't have a loop.
Yes, ours was a retrofit and the supply from the gas meter to the tank had to be increased from 1/2" to 3/4". A different style vent needed be installed in the roof and old one blocked off. Total install just under $4k for a 20-year warranted system. Hindsight, I would never do it again, I'd bank the $4k and pay my monthly bills for the thank water heater out of that. The absolute only blessing - and could be a curse in an accident - is there is an endless supply of hot water (and high gas usable) possible.
Another drawback, yes, "lukewarm" or close to that is not possible. As soon as the hot flow goes below the minimum flow setting, it will shut off. Our unit has dipswitches and we were able to set it pretty low, something like 2-3gpm before it will shut off. This is still challenging to take a "coolish" shower in warm weather, when the incoming water temperature is significantly higher than in winter. The incoming water temperature factors in also. Great idea, poor in practice.
Mine brings the temperature up in a few seconds, but in the meanwhile the "warmish" water in the pipe has been drawn, and is followed by "supply temperature" water (cold) for a few seconds until the superheated water arrives. Google "cold water sandwich".
This is the same as my experience, such as for a shower.
For washing machine or dish washer, I waste a lot of water bringing a stream of full hot into the kitchen or laundry sink before starting the machine. We keep the sink running until the appliance has satisfied its current water draw (if someone is taking a shower or filling a tub that can substitute, so we try to align to those things to save water). When the appliance next needs water (next wash or rinse cycle, etc.), back we go to the sink to bring hot water to the appliance by setting a timer! PITA for sure but we're trying to do our part in this drought.
On and off we have looked at point of use boosters. These tiny electric tankless or mini-tanks heat the water at each point of use fast and are meant to be used with a central supply. These idle back as hot water arrives from the main tankless and attempt to keep the stream above a certain setting (usually 120) and even out the tankless variability and cold water sandwiches.
They each need a dedicated 15amp circuit, are warranted about 3 years, and have been known to spring leaks. So not perfect.
I can live with waiting for hot water in shower and tub, but want them in kitchen for dishwasher and laundry room for washing machine due to periodic, low gallonage requirements. I do have room on my 200amp service and am still thinking about having this done. We need to have new outlets for each pulled from the panel, as we don't have any extra available, in addition to the installation costs. Not sure spending the additional cash is worth it given the relatively short lifespans predicted of the booster units.
The shower mixing valve should be able to provide whatever temperature you need by mixing the hot and cold water into lukewarm water.
The mixing valve can't create hot water.
There has to be hot water to mix with the cold. If the tankless heater shuts off because you want less hot water (lowered the hot water flow rate) then you end up with a cold shower.
I see, that makes sense.
Sorry for my list of inline posts. I'm new to this forum. I used the button to the right to "reply to" but my reply doesn't go under the person being replied to. Also, I guess I need to highlight or otherwise indicate the text I'm replying too. N00b. Sorry.
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