Propane tankless water heater

[HawkinsHollow]

I feel like there has to be something not setup right causing this.
Even the sink that is literally 4 feet from the heater takes 40 seconds to get hot. So I am hoping we can figure out the issue and make it hit the taps in less time.

 

[WinterDeere]

There is a valve in the pump that senses temperature in the line. The pump turns on at 85 deg and turns off at 105 degrees. The excess water is pumped back into cold supply line.

Yes, that is what I was thinking, if the tank/tanks were centralized this would help that.

I have to figure out some solution because waiting 50-60 seconds is unacceptable in my opinion. Lots of wasted water and time.

Okay, I could see this working, with a thermostat having a side differential on the pump itself. I was imagining a pump running all the time, and the tighter-differential thermostat in the heater itself working against this.

So then you have to be selective in where you install the pump, I guess? You'd probably want it closer to your point of use, if the thermostat is in the pump.

I feel like there has to be something not setup right causing this.
Even the sink that is literally 4 feet from the heater takes 40 seconds to get hot. So I am hoping we can figure out the issue and make it hit the taps in less time.

I've heard others (see post about my neighbor) reporting similar times, even for appliances close to the heater.

 

[HawkinsHollow]

Anyway to the OP take this is consideration. Our house is not very big and this time to tap is an issue. If you live in a big house or in a colder climate it could get much worse. I have since installing mine done more digging and lots of people have it much worse than we do. These things were not designed for large American style houses. They were designed for small apartments or flats where the pipes are more centrally located with much shorter runs.
At this point I have a bit of buyers remorse. I hope I can figure out a solution.

 

[HawkinsHollow]

Okay, I could see this working, with a thermostat having a side differential on the pump itself. I was imagining a pump running all the time, and the tighter-differential thermostat in the heater itself working against this.

So then you have to be selective in where you install the pump, I guess? You'd probably want it closer to your point of use, if the thermostat is in the pump.


I've heard others (see post about my neighbor) reporting similar times, even for appliances close to the heater.

Yessir! Installed at furthest faucet.

 

[ponytug]

Yessir! Installed at furthest faucet.

I have the same pump installed on our water tank, with a polymer bypass sensor at a remote tap. The pump is on a timer, and runs a few times a hour. It keeps the water warm at the remote tap for things like handwashing.

This version works well for tankless water heaters, and often the outlet is switched hopefully with a flip flop timer. That way you turn on the pump, listen for it to stop and use the hot water.

Because tankless hot water can vary a bit on temperature as demand shifts, I like shower valves that are temperature sensing, either mechanical or electronic, to keep the shower temperature (more) stable.

And yes, I do agree with that I think tankless work better in overseas situations where the homes are smaller, plumbing often added after the home was built, resulting in shorter hot water runs, often only a few feet. But, in many areas with harder water, the expectation is that there will be 3rd party maintenance, with plumbers stopping by (semi) annually as a service check to flush the exchangers, recirculate cleaning agents, and put the water heater back on line. It is a trade off for not having water softeners, and supported by less of a DIY culture (or by law) in many areas, at least in my opinion.

All the best,

Peter

 

[WinterDeere]

Yessir! Installed at furthest faucet.

I like that setup. I had been considering running one on my own, but was looking at doing a return line from the hot supply side back to the water heater, all in sweated copper. This makes much more sense.

But searching, most of what I'm finding is 3/4" NPT and capable of up to 10 bars pressure. Total overkill. Where'd you find that little guy?

Something that can be wall-mounted in the back of the cabinet under the sink, with 3/8" compression hose fittings to tees at the supplies like you have shown, appears to be ideal for this.

My coffee bar and pantry sink are about 60 feet from our kitchen and water heater, so it's a reasonably long loop (120' round trip) that I'll be heating. Pipe insulation is in my near future.

 

[HawkinsHollow]

I like that setup. I had been considering running one on my own, but was looking at doing a return line from the hot supply side back to the water heater, all in sweated copper. This makes much more sense.

But searching, most of what I'm finding is 3/4" NPT and capable of up to 10 bars pressure. Total overkill. Where'd you find that little guy?

Something that can be wall-mounted in the back of the cabinet under the sink, with 3/8" compression hose fittings to tees at the supplies like you have shown, appears to be ideal for this.

My coffee bar and pantry sink are about 60 feet from our kitchen and water heater, so it's a reasonably long loop (120' round trip) that I'll be heating. Pipe insulation is in my near future.

AquaMotion AMH3K-7 Under Sink Hot Water Recirculation Pump Kit with Timer

HotOne under sink circulator designed to deliver hot water instantly

www.totalhomesupply.com

Yes, I will be adding insulation to all of my hot water pipes as well.

 

[ponytug]

I like that setup. I had been considering running one on my own, but was looking at doing a return line from the hot supply side back to the water heater, all in sweated copper. This makes much more sense.

But searching, most of what I'm finding is 3/4" NPT and capable of up to 10 bars pressure. Total overkill. Where'd you find that little guy?

Something that can be wall-mounted in the back of the cabinet under the sink, with 3/8" compression hose fittings to tees at the supplies like you have shown, appears to be ideal for this.

My coffee bar and pantry sink are about 60 feet from our kitchen and water heater, so it's a reasonably long loop (120' round trip) that I'll be heating. Pipe insulation is in my near future.

To get tankless water heaters to kick on, there is a minimum flow that varies amongst the units.

That said try searching for Grundfos. They are the primary manufacturer of these pumps, both residential and commercial, and related pumps.

https://product-selection.grundfos.com/us/products/alpha-north-america/alpha-comfort-system?tab=models

All the best,

Peter

 

[WinterDeere]

Did a bit of hunting on these pumps. Lots of no-name crap out there, but the major brands all seem to include a timer I wouldn’t want or need. Any recommendations for a pump with thermostat only, and no timer? I’d rather manage timing by my home automation system, than have another independent timer to keep on schedule though every power outage.

 

[etpm]

Anyway to the OP take this is consideration. Our house is not very big and this time to tap is an issue. If you live in a big house or in a colder climate it could get much worse. I have since installing mine done more digging and lots of people have it much worse than we do. These things were not designed for large American style houses. They were designed for small apartments or flats where the pipes are more centrally located with much shorter runs.
At this point I have a bit of buyers remorse. I hope I can figure out a solution.

I live in a big house and already wait for hot water. So waiting for a tankless heater won't bug me. I already looked into a recirc. system and nixed the idea. Too much energy wasted.
Eric