tankless water heaters on demand

fishlessman

looking at electric to replace an oil fired tank heater in the basement ruined by flooding. anyone have a good rule of thumb on sizing. shower, clothes dryer for the big draw, two bathroom sinks and a kitchen sink for minor draws. gut feel says 5 gpm would work, get a 7 or 8 gpm model. seasonal application at the beach so end of june thru september. sinks shower etc within 15 feet total distance. i really want this upstairs and theres no real space for a tank in the house if i more it onto the first floor.

fishlessman

looked into a propane tank heater today, propane bottle needs a ballast cement pad that sits 4 feet deep so thats out. electrical box can handle a hundred amps for the 7 gpm tankless and fits nicely on the bathroom wall.  cold water connection and a hot water connection into existing plumbing and add breakers and wires for 4k labor seems a bit insane.......

Canugghead

We got our tankless gas water heater installed in 2005, touch wood it's still going well. IIRC we paid $2400 tank and labour all in. It needed exhaust through an exterior wall but no new circuit needed since it's 110V.

Back then it was a novelty and I didn't know better, the installer took short cuts or made honest mistakes. Just thought I'd share the shortcomings on mine with you:

1) It was missing the setup for flushing the system to descale as part of regular maintenance. I had to retrofit some valves myself for flushing.

2) I had to call him back to install the missing check valve per installation manual.

3) When the shower closest to the heater is in use, other hot faucets get very little hot water (not enough pressure); we've learned to live with it   I'm not an expert but I think it's because the installer had the 3/4" inlet and outlet reduced to 1/2" immediately at the heater. Perhaps 3/4" output pipe should run for some distance before branching out evenly to 1/2" hot faucets?

fishlessman

Canugghead said:

We got our tankless gas water heater installed in 2005, touch wood it's still going well. IIRC we paid $2400 tank and labour all in. It needed exhaust through an exterior wall but no new circuit needed since it's 110V.

Back then it was a novelty and I didn't know better, the installer took short cuts or made honest mistakes. Just thought I'd share the shortcomings on mine with you:

1) It was missing the setup for flushing the system to descale as part of regular maintenance. I had to retrofit some valves myself for flushing.

2) I had to call him back to install the missing check valve per installation manual.

3) When the shower closest to the heater is in use, other hot faucets get very little hot water (not enough pressure); we've learned to live with it   I'm not an expert but I think it's because the installer had the 3/4" inlet and outlet reduced to 1/2" immediately at the heater. Perhaps 3/4" output pipe should run for some distance before branching out evenly to 1/2" hot faucets?

Should probably down load a manual to see how the electric should be cleaned. It will be drained every September and turned back on in may/June. Going to hide a ball valve under the clothes washer to cut the hot water back on the washer and don't see much problem with that anyways as it's mostly used for sheets and towels anyways. Was looking at propane til I saw the outside tank requirements for the cement pad. The electrics are inexpensive at around 700.00 for a 7gallon per minute unit. The current unit is in the basement in a hand dug crawl space that makes replacement not so much fun. 

GregW

I work at a commercial HVAC company with a plumbing department- I have never heard anything good about instantaneous water heaters- either gas or electric. I asked again a couple of weeks ago about them for a family friend- I was advised again, to stay with a traditional tank. Maintenance issues and reliability were the primary complaints. They also mentioned that in their experience customers were disappointed with water temps and volumes.

Canugghead

My experience.

The bad:
* Definitely has temp fluctuation issue at start up. I remedy the problem with a small pump that runs on demand, controlled by a  smart switch.
* Volume is an issue when using multiple faucets, I suspect in my case it's bad planning/configuration.

The good:
1) Has been running with zero repair since summer of 2005, that's almost 19 years ago if anyone is counting, touch wood. 
2) Conventional wisdom says to flush/descale every six to twelve months as preventative maintenance. My heater was over 15 years old when I did the FIRST flush/descale.

The tankless ROI is probably better for empty nesters like us, i.e. lower demand and infrequent use of hot water = conventional hot water tank sitting idle for prolonged periods, compared to a young family with several growing kids especially teenagers. Teenagers+Tankless heater is a bad thing because they can take super long showers with no worries of hot water running out, lol.

I installed a wifi enabled central water main shutoff valve that can be activated by any of the strategically placed water leakage sensors. Shutting off the water main cannot stop a busted/leaky water tank from flooding the basement, so the peace of mind is a bonus for us.

fishlessman

GregW said:

I work at a commercial HVAC company with a plumbing department- I have never heard anything good about instantaneous water heaters- either gas or electric. I asked again a couple of weeks ago about them for a family friend- I was advised again, to stay with a traditional tank. Maintenance issues and reliability were the primary complaints. They also mentioned that in their experience customers were disappointed with water temps and volumes.

we used to have a 1950's heavy copper water heater running on oil. very basic, remove the burner and hang it high in the basement every fall as sea water pours in there routinely. lasted until about 12 years ago, going on a third heater now as they dont seem to like being submerged with the rising seawater the tankless will fit behind the bathroom door at an easy workable height on the first floor. showers with the 40 gallon tank last three or four people with hot water, ive had 50 plus people sleep over so volume might not be the biggest loss with hot water in the summer. these floods seem to be getting bigger, first time filling the basement to the ceiling studs. next problem is what to do with the hot air furnace, i say get rid of it all together but i know ill get out voted. family beach house with 4 votes makes it tough.....

fishlessman

so these expensive plumbers quote to remove the hot water heater, add a tankless on demand upstairs into the laundry room,add a hot water tank into the basement?, move and plumb the washer dryer into the laundry room, remove a forced air furnace, remove the oil tank....what we asked for was add the electric tankless and install it in the small bathroom and add a sub panel for power.........the furnace and oil tank has nothing to do with this and isnt part of the project, there is no laundry room, the tankless is just tying into existing, the washer stays where it is.......and what is the tank for............projects 2 hours away are fun.........

fishlessman

so the heating/electrical dude wires in the new burner for the furnace.......did you fire it off........there was no power........did you flip the breaker back on........they will be back in two weeks.....the breaker box is right next to the boiler and i would assume he would have made sure it was off before he started.........never assume

lousubcap

Since @fishlessman mentioned my least favourite (nod) word in the English language-a mini rant:
The word I have wanted banished from the language for longer than I can remember is "assume".  It is a cop-out that facilitates the user.  It is an enabler, interpret things as you want/wish them to be.  And that interpretation is likely not the true reality and certainly will skirt the tough issue that, in most cases will include a potential uncomfortable situation or scenario.  Thus the "assumer" shirks the responsibility of pursuing the correct answer.  Off the soap-box.

fishlessman

lousubcap said:

Since @fishlessman mentioned my least favourite (nod) word in the English language-a mini rant:
The word I have wanted banished from the language for longer than I can remember is "assume".  It is a cop-out that facilitates the user.  It is an enabler, interpret things as you want/wish them to be.  And that interpretation is likely not the true reality and certainly will skirt the tough issue that, in most cases will include a potential uncomfortable situation or scenario.  Thus the "assumer" shirks the responsibility of pursuing the correct answer.  Off the soap-box.

the breakers were off before he showed up, but a licensed electrician should know to check i learned my lesson with osha along time ago, bought a used lathe and was leveling it up, no power cord on it. big fine for not having it locked out and you really cant argue with osha........