Which Natural Gas Water Heater to Get?

[LoneRanger]

I thought the tankless can only produce a certain rise in temp on the incoming water. Our municipal water gets very cold by this time of year, maybe around 43 F out of the tap. I should measure it. That was a guess. Getting 120 degree (F) water out of a tankless with incoming supply in the low 40 F range... is that an economical solution? Wouldn't one have to get a pretty expensive tankless unit to get that done ?

 

[PandaBear]

Most tankless have much higher BTU than tanked water heater, so you need to make sure your exhaust is big enough or you can't install it.

 

[Donald]

Originally Posted by PandaBear
Most tankless have much higher BTU than tanked water heater, so you need to make sure your exhaust is big enough or you can't install it.


And a larger gas supply line.

 

[Wolf359]

Originally Posted by Donald
Originally Posted by PandaBear
Most tankless have much higher BTU than tanked water heater, so you need to make sure your exhaust is big enough or you can't install it.


And a larger gas supply line.


Right, the biggest is typically the 3/4 inch gas line as opposed to the 1/2 inch that may be feeding most water heaters. Then if you need a higher flow rate than what the gas meter is rated for, you have to have the gas company swap out the meter. I sell lots of houses and I rarely see them. The main problem with them is that very few plumbers know how to fix them, parts aren't easy to get at the supply house and once your warranty runs out, you may be SOL.

 

[MNgopher]

Originally Posted by LoneRanger
I thought the tankless can only produce a certain rise in temp on the incoming water. Our municipal water gets very cold by this time of year, maybe around 43 F out of the tap. I should measure it. That was a guess. Getting 120 degree (F) water out of a tankless with incoming supply in the low 40 F range... is that an economical solution? Wouldn't one have to get a pretty expensive tankless unit to get that done ?


All true. The lower the incoming water temp, the greater the required rise. This forces a bigger tankless unit to get enough rise in temp for the same flow rate. That also may trigger bigger input piping, etc... If your required flow rate is lower, this is less of an issue.

It boils down to this: do the economics make sense or is there a need for "limitless" hot water.

In our case, another tank will go in and last another 15 years with zero maintenance, even an anode.