A 13kw electric tankless would require one 60 amp breaker and give you 109 degree water at 1.5gpm with 50 degree incoming water.
Tankless to supplement tank for single bathtub
- Thread starter Luke Maddux
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All the hot water would need to be ran through a pressure balanced mixing valve with a temp limiting device.
The water heater thermostat itself isn’t considered a safety temp limiting device.
The water heater thermostat itself isn’t considered a safety temp limiting device.
We shall talk more later. I have some things to do.
That manabloc system sucks if you’re doing a true manobloc system where every fixture hot and cold gets it’s own valve and water line.
Don’t do it broski. Trust me
You’re installing a crap ton of pipe and you’ll be purging hot water at every fixture when you use it. Some people like that there are valves to turn off.
I see it as valves to leak and a crap ton of pipe to leak.
No need to complicate things. Build an efficient, simple system that doesn’t leak. That’s the objective. Adding unnecessary pieces to the puzzle is not desirable.
That manabloc system sucks if you’re doing a true manobloc system where every fixture hot and cold gets it’s own valve and water line.
Don’t do it broski. Trust me
You’re installing a crap ton of pipe and you’ll be purging hot water at every fixture when you use it. Some people like that there are valves to turn off.
I see it as valves to leak and a crap ton of pipe to leak.
No need to complicate things. Build an efficient, simple system that doesn’t leak. That’s the objective. Adding unnecessary pieces to the puzzle is not desirable.
I use a small 5gpm Rinnai propane tankless for my application (not a bath or shower though). This one Rinnai Value Series Outdoor 5.6 GPM Residential 120,000 BTU Propane Gas Tankless Water Heater V53DeP - The Home Depot is the closest match to mine, mine is the previous model to this one.
He says he doesn’t have a big enough propane tank for a gas tankless.
That’s what I’ve been trying to tell him with the numbers.
@Luke Maddux Do you have abundant sun where you are (and when you want to use the outdoor tub/shower)? You could consider putting water tanks on a nearby roof or other structure for solar heated water supply. This is a very cheap way to get solar heated hot water. (Nowadays most people just do solar panel arrays to generate electricity for use in anything. But there is still not a thing wrong with direct solar-heated water.)
Luke Maddux
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The solar thing is worth looking at, maybe. We do have a lot of trees though, so likely not viable, plus I don't know if my wife would go for that aesthetically.
Too late Re: the Manabloc warning, I finished the repipe this weekend. It's hard to illustrate this, but you'll have to trust me that repiping with a traditional trunk and branch wasn't an option without ripping out the floor in a huge chunk of our house. I could fish pex through this area though, I just couldn't crawl into it to make connections, so if we wanted to truly repipe the whole house, home run was the only way to pull it off. So far so good, we're really happy with the improvements it made in our pressure/temperature/wait time and I think that the number of fittings I avoided by making continuous runs from the Manabloc to the fixtures probably offsets the number I would've used in a traditional system. Our previous plumbing had a LOT of stupid issues that was clearly a result of either Pros trying to squeeze profit or amateurs making dumb mistakes.
If the power requirements for electric tankless heaters are truly as serious as they sound, then thats not really going to work for my application either. Marketing language speaks to the contrary and makes it sound like an 8kw unit can run a tub/shower, but I'm happy to trust the experience of others that it's not.
I think I'm going to try the following:
I'll install the tub/shower using my current supply (tank). If we determine that the supply is inadequate and every time we want to use the bath it frags our hot water supply, then I'll look at installing a tankless propane unit and just getting the propane tank filled more often. There's some nuance I hadn't considered, namely that the overlap between when we use our gas logs (our current highest draw propane appliance) and when we will use the outdoor tub probably isn't as much as I'd thought it would be, i.e. we use the logs all winter but probably won't use the tub in the absolute coldest months.
Thanks for all the input, I really appreciate it.
Too late Re: the Manabloc warning, I finished the repipe this weekend. It's hard to illustrate this, but you'll have to trust me that repiping with a traditional trunk and branch wasn't an option without ripping out the floor in a huge chunk of our house. I could fish pex through this area though, I just couldn't crawl into it to make connections, so if we wanted to truly repipe the whole house, home run was the only way to pull it off. So far so good, we're really happy with the improvements it made in our pressure/temperature/wait time and I think that the number of fittings I avoided by making continuous runs from the Manabloc to the fixtures probably offsets the number I would've used in a traditional system. Our previous plumbing had a LOT of stupid issues that was clearly a result of either Pros trying to squeeze profit or amateurs making dumb mistakes.
If the power requirements for electric tankless heaters are truly as serious as they sound, then thats not really going to work for my application either. Marketing language speaks to the contrary and makes it sound like an 8kw unit can run a tub/shower, but I'm happy to trust the experience of others that it's not.
I think I'm going to try the following:
I'll install the tub/shower using my current supply (tank). If we determine that the supply is inadequate and every time we want to use the bath it frags our hot water supply, then I'll look at installing a tankless propane unit and just getting the propane tank filled more often. There's some nuance I hadn't considered, namely that the overlap between when we use our gas logs (our current highest draw propane appliance) and when we will use the outdoor tub probably isn't as much as I'd thought it would be, i.e. we use the logs all winter but probably won't use the tub in the absolute coldest months.
Thanks for all the input, I really appreciate it.
