I am renovating my old farm house and will be replacing all the plumming, I currently have a 60 gl boiler that is only about 5 years old, however people are telling me to change to a propane water on demand system as it is cheaper to run and you are not constantly heating the large tank.
So my dilema is do I stay with the tank or spend the 3k for a new system.
4 bed house, 3 bathrooms, laundry room, just 2 of us living here FT, but will be selling it within 5 years.
Thx
Dave
Replies
Keep the tank. Use the $3k elsewhere. You'll never make it back in energy savings during your time there, and it will not add anything to your sale price.
How long wil it take you to save $3K using propane? If you save $10.00 a month it will take you 5. years and 8 months just to get your money back. At 5 years 9 months you'll start saving $10.00 a month.
Who cares what 'people' think? It's not their wallet on the line.
Asking about the type of heater is like asking what sort of motor your car needs. There's no set answer, and the heater is only part of the system.
For a tankless heater to work to it's best potential, it needs to be part of a PEX "manifold" plumbing system. I suspect it is the manifold distribution arrangement that really accounts for the energy savings anyway, rather than heat losses from the tank.
I have also the the manifold system, running 3/4 flex to the units then 1/2 flex to feed, so adding the water on demand would improve the flow, does that mean if I put a manifold system in then the boiler won't be as efficient ??
I understand the cost will be very difficult to recupe also iunteresting to know it wont add any real value.
Thx
Dave
The only time tankless actually saves energy is when you have, eg, a weekend cabin that is unoccupied most of the time. In a normal home environment you will lose money, even ignoring the up-front cost. This has been shown repeatedly. The only reason for going tankless would be if you simply did not have the room for the tank.
(Keep in mind that a modern tank is VERY WELL insulated, so the "standby" heat loss is miniscule. And a tank burner is far more efficient than the tankless one, for several reasons.)
Put $10 worth of extra insulation around HWH, added inverted siphon (anti heat convection out of WH)
went on vacation,
2 weeks later looked at meter, used $1.35 worth of energy for standby.
$2900 difference for demand, even if no standby losses, $35 year "savings", and even at 1% interest you lose $29 interest, so you 'save' $6/year
ONLY takes you 483 YEARS for 'payback', assuming tankless lasts that long.
Put $10 worth of extra
oops, duplicat
Code in most areas now requires "heat trap" fittings on the in and out of the water heater, serving the same purpose as your inverted siphon.
Tried living with one?
A tankless heater may be OK for a one person home, two people - if you know at all times where the other is and what they are doing.
If you are taking a shower and someone turns on the hot water elsewhere, you freeze. You cannot turn off the hot water, without the boiler doing a run check, meanwhile cold water is pouring over you for 28 seconds. If someone turns on the cold water you may burn.
If you have a tankful of water this will come in handy when the water supply stops for some reason, especially if you have young children, if you want to flush the toilet, you do not want to be driving about looking for somewhere to buy bottled water in the middle of the night. Running warm water to rinse dishes is impossible - its on too hard, to hot.
When you live with a tank that can supply water at any temperature you care to set and any flow rate, where several people can use the hot/warm water at the same time, you know you got it right.