I just noticed that my hot water tank is approaching the 10 yr mark, which I understand it pretty much all you can expect before it starts to leak. Should I replace it now, is 10 years too soon or after it leaks?
If I were to replace it I am considering a tankless water heater as I like the idea of saving money on fuel, but want to know how effective they are. I did ask this a few years ago, but thought I’d get some new opinions. Some info: I’m not going electric, it will be gas heat. I am have a well system that varies pressure from about 40 to 70 PSI, which does cause a unsteady flow at the showerhead as the pump cycles on and off, is this going to be a problem with the tankless system? What sort of energy savings can I expect?
I have heard tankless water heaters are not all they’re cracked up to be, as the payback period is pretty long. I’m sure some other dopers will do the research and find out the straight dope on this.
I looked at a whole-house gas tankless earlier this year, and the payback period vs the added cost was very nearly the expected life of the unit - the thing itself costs much more than a traditional tank heater, and there are considerations like needing an electrical circuit run to power the ignition and retrofitting the flue vent - the 3" vent that’s OK for a tank heater isn’t enough for the extra BTUs kicked out by a tankless.
Aside from the added costs of installation, the end-user experience would be exactly the same as with the tank heater - we’d still have to wait a few minutes for the hot water to arrive. So, I bought a premium-grade tank heater with a 12-year warranty and extra insulation.
If you can install a tankless heater without a costly instalation they are the way to go. They work very well. One of the things that makes them very costly to install is often older gas lines aren’t large enough to provide for a tankless heater. I’d look into that before much further thought.
On to your well. If you can notice to pump turning on and off by the presure at your shower thats indicitive of a problem. Could be the tank is waterlogged or the diaphram could be bad. Could also mean the tank is sized to small for the pump. 40-70 is to large a range. Standard pressure settings would be 40/60 or 30/50.
10 years isn’t the end of your tank. You can pull out and replace the anode in the tank. The anode corrodes before the tank does, and if the anode is used up it can be replaced.
If it’s not leaking now, I say replace the anode and wait another 5 years.
I don’t have any experience with a tankless unit, although it would work well in my house, as the water heater is not close to either kitchen or any bathrooms, and it takes a while to get hot water to those faucets.
However, a 10yro heater isn’t necessarily on its last legs. Mine is still working after 45 years (electric), the anode has never been replaced, and it doesn’t leak. Probably not as efficient as the newer ones, tho.
But about your surging problem with the water pressure…usually there is a setting on your pump controller for the start & stop values. Mine is set for 30-50 lbs and the difference is barely noticeable during a shower. Also, see if your pressure tank is working and/or can be replaced with a larger unit. If the bladder is broken, or the air cushion is not there due to a leak, the pump will start & stop more frequently. A larger unit will smooth out the changes, too.
Also, if you ever have to replace your pump, consider a smaller unit. As long as it is adequate to handle the maximum flow needed, the cycles will be more gradual and less frequent.
We used to have a “tankless.” I hated it. It was hooked up to our central oil heat system, which meant the oil burner had to run both summer and winter to keep us in hot water. If you used a lot of hot water at once, say from running the dishwasher and then taking a shower, we’d run out of hot water. Of course, it was first installed in the 1950s when the house didn’t have such a thing as a dishwasher. Finally, since our well water is rather hard, with lots of calcium, deposits would build up inside the coil fairly often, necessitating the annoying job of either replacing or cleaning it. The alternative would have been installing a water softener, with its own accompanying cost and maintenance.
I’ve experienced tankless heaters in Europe, sometimes for weeks in a row, and I have to say that IMO they suck. The water temperature is not consistent, in some cases fluctuating wildly from lukewarm to scalding to lukewarm again in the shower. The water pressure fluctuates as well - this makes it just damn hard to like them when you go from fast and lukewarm to slow and scalding on about a 5-second sine wave. This is not just in one or two places, but many in the UK, France, Spain, and other countries. I know that European Dopers are likely to come in and say “pish-posh” or something, but in my experience they (the tankless heaters) just are not up to the task for most people who are used to a large tank heater.
(FTR, I love the concept of tankless, and recognize the efficiency improvement. I’m all for them - except that my experience has been so poor. However, my new 50-gallon heater seems to be so well insulated that even with a 160F water setting, the top of the heater is cold to the touch (whereas my old heater, at 145F, was always about 100-110F), so IMO there really cannot be that much heat loss from a new, very well-insulated tank heater.)
As to the OP question of early replacement - I don’t think I would replace the heater early, unless a new heater would give you a great energy savings too. Looking at the “expected annual consumption” figures of my old versus my new heater, my new heater pays for itself in about 4 years just in the gas savings.
We have an electric one that has some issues. Most mornings it has turned itself off and has to be reset. I know that is just the thermostat but I think the thing is damn near 20 years old, and I think it leaks a bit.
Anyway, since the last time it was replaced the city has run gas lines to our house and we are concidering going gas this time, my husband has fond hopes of doing the tankless. I am starting to think that may not be the way to go. Maybe running the gas into the house isn’t worth it but we hope to do gas for the dryer when it gives up, so we have to go that way at some point/
We had a gas tanked heater that the bottom fell out of last year. We replaced it with a tankless (the Rinnai).
We’ve had no problems with it, except for a small leak (not in the tank itself, fixed by the gas company). It takes a few more seconds to kick in the hot water compared to a tank, but otherwise you’d never notice unless I told you we had one (except that you can take endless showers).
Just for note - we never run a water appliance and shower at the same time, so can’t comment on that.
I’ll add my experience here, although it is different from the US tankless water heaters. Our water heater (we live in a 4-year-old rented duplex, so it’s pretty new) appears to have a small tank (maybe 15 gallons?) that is heated on demand. You push a button to turn the heat on before you get in the shower or wash dishes. It takes about 15 seconds from the time you push the button to the time the shower is running hot. The water temp is completely consistent during the shower, and has never run out on us. It works extremely well, and is very efficient. It runs off kerosene; $50 worth lasted us 8 months (two adults, two dogs, lots of beach stuff to clean every time we go to the beach or scuba diving).