This seems to be a very common problem as it is not always readily explained or understood that tankless water heaters cannot always contend with the combination of low inlet temp and high flow. Thus, I fell victim to the appeal of the tankless on-demand water heater.
I recently bought a house and did a remodel, replacing the non-functional leaking tank heater that was over 25 years old with an Eco27 by ecosmart. It has worked well until I installed a higher flow rainfall showerhead in the shower that pulls about 4.4 gpm. Living in Oregon with inlet temp from our well being about 55F the best that it can manage is 85-90F which is just under a fairly comfortable shower. All this while not being able to run any other hot water taps or appliances.
After scouring the internet and reading post after post on many different forums I think I have a couple different options and want to know what would be the best to move forward with.
In no particular order:
-Energized low-temp setpoint tank style water heater piped in series before the tankless. In theory providing already semi heated water to the tankless heater making a larger temp rise easier. Downsides being extra energy use for maintaining temp and not knowing if the Eco27 has a max inlet temperature (awaiting email from ecosmart)
-A smaller tankless water heater in series just before the larger one. I have the space on my electrical service which is 200A but would adding another small one just before really make that much of a difference or just be a waste of money and energy? I also realize it will double the min flow rate for activation which is 0.3gpm for most ecosmart models making it harder to activate with low-flow fixtures.
-A tempering tank placed somewhere that would allow incoming water being used for hot water to increase in temp via heat exchange with the surrounding interior. downsides being I don't have room underneath my house for a large tank which means i'd have to put it into the pantry next to the tankless one. Plus our house stays relatively cold most of the time since we use minimal heating.
-solar pre-heaters mounted on the roof. I couldn't find much info on this. We definitely have a south facing roof that I could mount something like this on but again, running up against the issue of not knowing if ecosmart has a max inlet temp.
I would love input on any of these options as well as others I may not have considered. I have ample ability to do different plumbing configurations and wiring configurations as I have a friends who are professionals and will help for free/beer.
Specs/details
Eco27 27kw tankless water heater
inlet temp: 55F
max flow desired at 105F: 4.5gpm
electrical service: 200A
I recently bought a house and did a remodel, replacing the non-functional leaking tank heater that was over 25 years old with an Eco27 by ecosmart. It has worked well until I installed a higher flow rainfall showerhead in the shower that pulls about 4.4 gpm. Living in Oregon with inlet temp from our well being about 55F the best that it can manage is 85-90F which is just under a fairly comfortable shower. All this while not being able to run any other hot water taps or appliances.
After scouring the internet and reading post after post on many different forums I think I have a couple different options and want to know what would be the best to move forward with.
In no particular order:
-Energized low-temp setpoint tank style water heater piped in series before the tankless. In theory providing already semi heated water to the tankless heater making a larger temp rise easier. Downsides being extra energy use for maintaining temp and not knowing if the Eco27 has a max inlet temperature (awaiting email from ecosmart)
-A smaller tankless water heater in series just before the larger one. I have the space on my electrical service which is 200A but would adding another small one just before really make that much of a difference or just be a waste of money and energy? I also realize it will double the min flow rate for activation which is 0.3gpm for most ecosmart models making it harder to activate with low-flow fixtures.
-A tempering tank placed somewhere that would allow incoming water being used for hot water to increase in temp via heat exchange with the surrounding interior. downsides being I don't have room underneath my house for a large tank which means i'd have to put it into the pantry next to the tankless one. Plus our house stays relatively cold most of the time since we use minimal heating.
-solar pre-heaters mounted on the roof. I couldn't find much info on this. We definitely have a south facing roof that I could mount something like this on but again, running up against the issue of not knowing if ecosmart has a max inlet temp.
I would love input on any of these options as well as others I may not have considered. I have ample ability to do different plumbing configurations and wiring configurations as I have a friends who are professionals and will help for free/beer.
Specs/details
Eco27 27kw tankless water heater
inlet temp: 55F
max flow desired at 105F: 4.5gpm
electrical service: 200A