What’s the best instant hot water heater for the average 2 person home? Looking for different brand name evaluations.
Consumer Reports considered the options from various brands so identical performance-wise (both gas and electric) that they don’t even recommend individual brands or products for any type of water heater. They do have some caveats around making the switch to tankless, should you be so inclined.
Do you have access to natural gas or propane? Note that the ones run on electricity don’t work very well and aren’t really worth consideration unless you have no gas.
I have a Rinnai - a big name in tankless heaters. Rheem is another big one.
ETA
This may not be very fair to the electric tankless as I did my research on tankless heaters back in 2006 or 2007 and most sources back then gave big thumbs down to the electric units.
Electric units may have improved by now.
I kind of doubt there’s been much improvement, given there’s still going to be a resistance heater at the heart of it.
Yeah…how much improvement can there be? It’s heating water. As old as human society.
You can change energy sources, maybe eke out some efficiency with better engineering. But I doubt there is a lot of room for improvement here and most homes will force you to one energy source (electric or gas).
If the OP wants the “best” I suspect that will come in build quality and warranties and price and for that you just have to do the homework comparing brands.
I think the bigger question is whether to go with a gas or electric model. Googling, an electric one appropriate for a whole house might require 80 or 100 amps, just for the water heater, in addition to whatever else the rest of the house needs. Similarly, the instant gas heaters might require you to upgrade your gas service.
The problem is, if a home has no gas service then electric is your only choice.
If they have gas service then I guess they can choose either one (assuming the electric and/or gas has sufficient capacity).
Well, it might be possible to get a large propane tank in the backyard and still go for the gas type.
I have a Takagi system that’s been working seamlessly for seven years now. It’s propane, I have a 100 gallon tank for water heater, home heating and cooking that gets filled usually twice a year. Even in the dead of winter when the water comes out of the tap barely above freezing my showers always need some cold water to make them bearable and never running out of hot water is absolutely sybaritic.
Is there an issue with gas pressure if it gets really cold outside? I have read that in very cold temperatures (say 20F or lower), if the tank is less than half-full, you may not get enough pressure to run gas appliances.
I’ve spaced out and run the tank down to under 10% of capacity and it still worked fine–I don’t faff about playing brinksmanship games with heating fuel in winter though, but I do forget to check it in summer. Actually, when I first installed it but they hadn’t dropped the big tank yet I found I could run the water heater off a 40# tank down to about half its capacity but it would run out pretty quick. Only needed to do that a few days though.
Since I am in the UK, I can’t advise you about brands. We have been using this kind of water heating for both hot water and heating the house (wet radiators). Ours is gas, but now the Greens say that is bad for emissions. We will wait and see what happens.
A few points to note:
They need a vent (flue) to the outside and good ventilation on the inside.
Location is important - long pipe runs are wasteful as you have to wait while the hot water reaches the tap and you leave them full of hot water after. Since our bathroom is above the kitchen, it was easy to decide to hang it on the kitchen wall. (They are very quiet in operation).
You can adjust the output temperature at the heater. If you have children or elderly in the house, you don’t want to scald them.
The hot water comes through at mains pressure, but the heater can only heat x gallons a minute through y degrees. If you want a decent flow of hot water in a shower, you need a heater that can provide it.
Annual servicing is important. As with any appliance you need to know that you can get it fixed if/when it goes wrong and a service will include checks to ensure that there are no leaks of harmful gasses.
I’d only do an electric tankless heater if there was a pre-heat tank run off of something like a heat pump and kept around 80ºF or so. That’ll significantly reduce the load on the tankless heater since it’s based on flow rate and incoming water temperature. Basically that makes the tankless heater a booster rather than the only heat source. An advantage to something like that is you can have two or three smaller tankless heaters closer to the point of use, like if the master bathroom is on the opposite side of the house as the kitchen. The “hot” water pipes between the pre-heat tank and the tankless heater would never be lower than room temperature either unless they happen to run through a crawl space, which should still be warmer than cold water from the street/well.
Thanks for all the thoughtful comments. At present our domestic hot water is supplied by an oil fired boiler - which also supplies our FHW baseboards. In the off season (as far as heating is concerned) the boiler only fires for domestic hot water. And heating oil here in New England is getting progressively more and more expensive. Electric is definitely out - electric rates are spiking even faster than oil. We have propane service now and will probably go that route. There’s just two of us here now and I can’t see continuing to store a big tank of hot water 24 hours a day, 365 days a year.
I had seen stories that there was very little difference between brands in the propane line and that seems to be holding true. Guess I’ll check with my local propane dealer and my local plumber and see what they recommend at what cost.
Good idea. The disadvantage to a tankless heater is that if it fails you can’t just pop over to Home Depot and walk out with a new one. So your plumber/HVAC guys would know what brands have parts availability at local supply houses (hopefully it’s not none of them but I wouldn’t let that be a deal-breaker).
My FIL told me that is the reason oil heating is used in New England. Propane is a liquid at -42 C, and butane a liquid at -.4C. -42 seems rather unlikely to me, but perhaps it is close enough to make propane difficult to vaporize.
I hope spmeone who knows better than I will give a better explanation.
Heating oil is also pretty common in the Philly area in neighborhoods where gas lines were never run or where the houses are old enough to have been converted from coal. When I was a kid we had a neighbor who still used coal. It was pretty cool to watch it being delivered from a truck down a chute into the basement.
I investigated tankless heaters about 3 years ago, but decided to replace my heater with a conventional tank type instead. Here are the reasons. YMMV.
I don’t have gas or propane, so electric is the only option. My service is 100 amps, adequate for my entire household, but insufficient for tankless electric. Upgrading would be expensive.
My water is from a private deep well, and although I have a whole-house filter, it is relatively high in particulates and dissolved iron. This would clog a tankless pretty fast and require frequent maintenance.
I then considered a tankless for one bathroom and the kitchen, which would be smaller and serve only one faucet at a time. Most require 240v, so I would need a new line to each area or accept a lower performance. I concluded it wouldn’t be cost effective, either.
Since this question is about seeking advice, experience, and opinions, I’ve moved it to IMHO.