I have a coal wood boiler, I have a indirect water heater and a domestic coil in it. 6-7 months out of the year I didn't need the tank water heater and I would just keep it on and feed the boilers hot water (makes 130-150 degree water). It no longer made sense to pay for the ridiculous cost to keep the old water heater in use. It is October and the boiler is off and I took a shower on a 1.25 gpm shower head, I could tell no difference. Water coming in is 55 degrees, however the ambience of the basement heats the 40 gallon indirect water heater and boiler at around 68. These slightly warmer temps help even if the system is off, factor that in to your equation.
Some advice
install a 1 micron water filter before the unit, these only fail because calcium or sediment cakes and cooks the unit. This is still a problem for tank heaters as calcium deposits will burn up heating elements in the tank units also. Hard water is significantly reduced by whole house filter, I have had my water tested before and after I installed them years ag0o. I have a 80 percent reduction in calcium and almost entirely reduced sediment. My solution is 5micron washable-5 micron carbon disposable-1micron activated carbon disposable- 1/2 micron disposable. I have a strainer in front of the tankless. The filter setup is more reliable and cheaper than a water softener. If you have a water softener you still need a filter before the tankless unit.
It makes no sense today not to have a lower flow shower head, It takes zero adjustment to the lower flow and the shower head saves cost on hot water. Lower flow shower head will make all the difference on saving money with this application.
The unit uses a special compression fitting that is supplied with the unit and make sure its properly put together.
| Brand | Rheem |
|---|---|
| Product Dimensions | 8.25"W x 12.63"H |
| Color | Gray |
| Wattage | 8 KW |
| Voltage | 240 Volts |
| Heat Output | 8 Kilowatts |
| Maximum Operating Pressure | 150 |
| Maximum Pressure | 150 Pound per Square Inch |
| Mounting Type | Wall |
| Manufacturer | Rheem |
| Part Number | RTEX-08 |
| Item Weight | 6.4 pounds |
| Country of Origin | China |
| Item model number | RTEX-08 |
| Is Discontinued By Manufacturer | No |
| Finish | Stainless Steel |
| Shape | Rectangle |
| Installation Method | Wall Mount |
| Item Package Quantity | 1 |
| Certification | certified frustration-free |
| Usage | Inside; Professional |
| Included Components | Fittings, Aerators |
| Batteries Included? | No |
| Batteries Required? | No |
