Propane Hot Water Tank heater or Tankless? Help me decide.

[aczlan]

We stayed with some friends who had a tankless water heater. At their house, unless you ran the hot water at the sink full blast, the water heater would not turn on. The tankless units will not heat water if the gpm flowing through them is too low. So if you like to run water in the kitchen sink at less that full blast so you don't splash water everywhere, you won't get any hot water.

I don't know if there are settings you can change on the tankless heater to make things better. We were considering tankless for the house we were building, but the experience at our friends house changed our mind. We didn't want to chance it unless we could first see a system working to our liking. We ended up putting a gas tank water heater in our new house.

I have seen that on some tankless HW heaters. Its usually because they have a cheap flowmeter, a cheap gas control valve, or someone hasnt been maintaining it and the flowmeter is gummed up.
A good tankless HW heater should not do that.

Aaron Z

 

[Gary Fowler]

I thought about a tankless HWH for my new house but decided against it for cost, maintenance etc needed to maintain the warranty ie yearly cleaning from an authorized company rep which I am sure would be at least $100. We did have one in an apartment in Peru that worked fairly well for just the wife and I and the HWH was only about 20 feet from any needed source.
I went with a standard 60 gallon electric water heater with a thermostat controlled recirculation pump and line to each outlet. This keeps the water hot to just below the valve and hot water is available within seconds of any outlet regardless of how far it is from the HWH. I did this because it saves a ton of water every month since I don't have to run 10 gallons to get hot water to my shower like I did at my previous house. Water is becoming a high dollar commodity more and more each day with the water bill almost par with electric bill in most places so I want to save every gallon I can. You cant do this with a tankless HWH so you waste much more water.

 

[V1Rotate]

I have a tankless system that also heats my house. I have no problems with running small amounts of hot water from the faucets, the water gets hot even at low flow rates.

 

[JPRambo]

I had a propane w/h installed when I built my home 20 years ago. With softened well water the tank lasted 6 years. We replaced the w/h (under warrenty) with another propane wh. It lasted about the same length of time. I replaced the w/h with electric (I am an electrician and can sweat pipes well enough to replace wh). I also put a timer on the wh. Timed it so most times it will heat when we are using hot water (showers, washing clothes and dishes etc.) during the day water is hot enough to wash hands and short showers, and other uses.
The propane w/h was great after the hurricane went through the area and we were the only home with hot water for showers, with a generator for the well water. (No power for 10 days)
I have also put in circuits for instant hot water heaters and found that lights will dim when they are heating. Here in SW Florida FPl does not install power lines to the house meter for this amount of power usage. If it is possible for the homeowner of a new home under construction (or after) to have the power company install a larger wire to the meter (at owners expense) this dimming with not happen.

 

[the old grind]

My brother's experience was with a 12 gpm Paloma (~$1500, then) that I installed for him in the very early 90's. He'd been reading New Shelter mag and every new gizmo offered the promise of being either 'more green' or 'more economical'. One thing he'd hoped to remedy was a 3-4 minute wait for HW after chasing and pre-warming 45' of 3/4" copper pipe. Without heat conducting/convecting to preheat the first several feet of outlet pipe there was no noticeable change. Temp regulation was acceptable, and the 'two-showers-at' once was never fully tested, nor was NRG cost/time ever evaluated. Much happier as a user (performance) than as a buyer (better somehow for $$?), he replaced with a NG conventional.

Recent dissatisfied new home buyer wanted daughters to girlie-up for school, and volume/flow was his expressed primary concern. Both gas and elec have flow meters to regulate the heating unit's output, but these aren't continuously variable as one might assume and typically have 'stepped' responses to flow. Intersting to me that he'd notice a temp issue with lav faucets apparently triggering step adjustments that surprised anyone showering, but that got him rattled within weeks of moving in. Again, plenty of HW, just not as consistent as the 'digital' promise. We're liable only for our installation quality, and the builder and HW maker can shuffle about the product fulfilling its good intentions.

We've seen recirculating setups like Gary's often thumbsup:, btw) in homes as well as hotel/apt setups. The usual 'return' connection to a tank is thru the boiler 'drain' loc, and home-brew jobs are often thermo-siphon (meh) vs the more consistent circulating pump that would also be used with a WH for boiler heat in a cabin or addition. Wrapping pipes is key to keep NRG costs down but, if I didn't mention it elsewhere .. thermal loss from a WH in the heating season theoretically supplants the furnace vs being totally wasted as one would assume.

I'm happy with a NG 40gal conventional, but like others locally with highly-calcified water there's a particular urgency to regularly drain sediment to prolong efficiency and WH life, a task as easily overlooked as scheduled checks of a bladder supply tank's air charge to prevent rupture. btw: I've looked into de-calcifying systems. They are plumbed in and have regen cycles like softeners but do not soften. Their 'matrix' affects crystal structure and re-crystalized clumps are supposed to modify others attached to downstream pipes/fixtures/WHs to be flushed out to drain or septic. Shows promise despite cost to 'try out', but YMMV as usual with varying water quality & minerality. Haven't seen one in use yet, so looking for customer reviews vs just promotional info. :2cents:

IMO, propane or NG conventionals are best appreciated during power outages, as mentioned above, and of course not many generators will operate a full-sized electric. btw: my brother had a point of use (small, elec for ease of inst, seller's installer vs us) instant-on added to his upstairs bath and we both agree that is where these babies really shine. :dance1:

 

[FTG-05]

I thought about a tankless HWH for my new house but decided against it for cost, maintenance etc needed to maintain the warranty ie yearly cleaning from an authorized company rep which I am sure would be at least $100. We did have one in an apartment in Peru that worked fairly well for just the wife and I and the HWH was only about 20 feet from any needed source.
I went with a standard 60 gallon electric water heater with a thermostat controlled recirculation pump and line to each outlet. This keeps the water hot to just below the valve and hot water is available within seconds of any outlet regardless of how far it is from the HWH. I did this because it saves a ton of water every month since I don't have to run 10 gallons to get hot water to my shower like I did at my previous house. Water is becoming a high dollar commodity more and more each day with the water bill almost par with electric bill in most places so I want to save every gallon I can. You cant do this with a tankless HWH so you waste much more water.

I just did that on my Rinnae (SP) tankless water heater. It's not that big of a deal. 3-4 gallons of white vinegar, a $9 set of washing machine hoses from Lowes, a five gallon bucket and a small water pump. Took about an hour or so. Pretty black stuff came out after about 15 minutes or so....

Good luck!

 

[skyhook]

IMHO, the cheapskate way forward for the OP's question is to replace the anode, which will be about $40 if you get the "smelly water" kind (they work for me) , and less if you just have a regular one. About 5 years down the road, change it again.

It is a very good bet that this simple maintenance will keep your present tank alive for the next 10 years. I kept a 50 gallon tank going for ~25 years by changing anodes every 5 years. Then the house burned down, so there is no telling how long it might have lasted.

A little off topic, but,,
I was told by a wise old man that "if' you completely remove the anode,
you will no longer have that "egg smell"...he was right.
5 years now with NO anode, no smell and tank is just fine.
I was told, "the anode" creates a chemical reaction with "well water" causing the smell.

 

[AHNC]

a couple thing about tankless. They work fine on cold water as well as on warm ground water. It is all based upon flow rate and burner input. At 70* rise my tankless (Rinnai RL75, 180,000 btu) will make 4.3 gallons of hot water/min all day long. If my ground water only required a 60* rise my output would increase about .3-.4gpm. On my last home I had a tankless for 12 years and never touched it. that was city water and good city water. If you have manky water, yu need to treat it or do the vinegar flush.

I chose the RL 75 because it has a .4gpm activation rate and a 10kbtu min fore rate. With the low flow faucets the minimum is more important than the max. Also, consider where your current water heater is located. Perhaps it is best to re-locate the new water heater to get closer to the rimary points of use. In other words, don't exacerbate the mistakes of the original low cost bidder. I just remodeld the house and all new piping for the new baths, laundry and kitchen. I was able to position the tankless so the longest run of any hot water pipe was 16'. As well, when you analyze the piping system keep in mind that the tankless will only make hot water when the fuacet is open. What that means is, pipe size matters. Cross sectional area of 1/2" pipe is .19 sq in, 3/4=.44 and 1"=.77. So, you have about 230% of the vol to move out of 3/4" that you have in 1/2. Look at the flow rates of the faucet and consider pipe size in your application. I'm not saying re-pipe the whole place but there are oplaces that you can modify. For instance, in my last home the water heater was farthest from the kitchen sink...and we were both pissed. It was fed by the 3/4" main. I came of the bottom of the unit and ran a 1/2 pex line direct across the basement to the kitchen sink and reduced the wait by about 70%.

Anyone who is a fan of tanks will want to buy a new one prior to 4/15/15 when the new Energy Codes come out. The tank guys are going to have to increase their Energy Factors all the way up to .62. That will be on under 55 gallon. Above 55 gallon will have to be I think it is .80EF.

I have to acknowledge my bias on this topic. I represented, Rinnai, the largest tankless manuf for over 20 yrs. I am a fan. When I put in my first tankless in my homw my gas consumption dropped by over 2/3. YMMV

 

[rafski]

I have had the whole house Seisco RA-28 Electric Tankless Water Heater for about 7 years now and it works great. The most difficult part of the installation was running four 30 amp circuits to it. Another thing I like, it senses the input water temperature to determine when to heat. This is great if you have other sources of heating in series with it. I have a geothermal heat pump desuperheater feeding mine. Even without the heat pump I used about $10 to $12 /month of electric.

Amazon.com: Seisco RA-28 Electric Tankless Water Heater. Four-Chamber. 95,560 BTU. 28kW + FREE Breo Watch: Home Improvement

 

[ultrarunner]

I have electric tankless, NG tank, Propane Tank and Electric Tank... they all have their place.

Hard to beat gas for simple economy.

Yesterday, replaced an American branded 30 gallon gas I installed in an apartment in 1992.

22 years of flawless service in a two bedroom apartment with a family of 4.

I did put a pan under it piped to the outside and the downstair's neighbor called to say water was coming out of a pipe at the back of the building.

I paid $88 for the 5 year warranty heater from Home Base...

$4 dollars a year or 33 cents per month!