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water heater

Time to replace my 18 yr old State nat gas water heater. I have a Weil-McClain nat gas boiler w/83% efficiency. Does it make sense to install an indirect water heater w/this efficiency?

Re: water heater


Yes it does, absolutely---you'll save big time if you install an indirect!

I've been involved with indirects for the past 30 years---they give far superior performance and good economy over anything else out there.

While they do require a higher up-front cost over a gas-fired HWH, you will still realize savings in fuel usage and unit longevity that will more than make up for the initial cost.

With an indirect there are no flue losses---they obtain their heat from the boiler as a heat exchanger---the extensive insulation keeps the water hot for a long time---since there is no wear & tear on the unit, they last for decades.

Some contend there are higher fuel losses during the summer when the boiler must remain active----not so--numerous tests have demonstrated the small amount of fuel used even during summer months.

You'll be kicking yourself that you waited so long before switching to an indirect.

This can be done as a diy project if you're handy---expect a unit cost of approx. $700 plus parts for connection to the boiler via a zone valve or circulator zone.

Recommended units would be Triangle Tube Phase 3, Weil-Mclain Gold Plus, TFI Everhot, Lochinvar Squire, Viessmann Verticell, and Amtrol Boiler Mate---the best performing units are usually a little more expensive because they have a stainless steel shell inside them (true of all of the above except the Amtrol, which uses a copper coil)---however the Amtrol is also a good unit & costs less.

The sites below compare different types of HW heating & sing the praises of indirects.


Re: water heater

Thanks for the info on the water heaters. I did not mention this when inquiring about indirect vs direct HWH, but I have 30% of my house w/hydronic floor heat operating on a separate thermostat (via TACO relay switch) from the rest of the house, which is standard HWBB. Do you see this as a problem?

Re: water heater

The indirect should be wired to receive priority over all other zones. The only other concern would be if you had an outdoor reset attached. The indirect again would need to override the reset control. the only thing i would add to nashuatech's post is Super Stor Ultra brand is a recommend but the amtrol boiler mate is not. They are the brand I replace the most because their not stainless steel, also because they've been around longer too.


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