Three weeks ago I completed a project I had planned to do for quite some time.
I removed my 500 watt heater plus one of the two 250 watt backups and replaced the main heat source for the tank (300 gallons total) with a system I designed as an additional zone off of my forced hot water oil-fired home heating system.
My main concern was the heat exchanger. Copper was out, so I got some flexible PVC tubing (red) from Lowe's (100 ft - approx $25.00) and some 90 degree 3/4 fittings. I figured that the PVC is not as conductive as copper so I "guessed" at 100 feet to submerge as the heat exchanger. No copper can touch the saltwater. I got a zone valve ($80 at Lowe's) a project box I had planned for my ATO, 1-120 volt coil solenoid, some connectors, wires of various purposes, leftover 3/4" M copper pipe, fittings, other small stuff and I was on my way. I plumbed the feed an return to the basement sump room and to the 150 gallon sump from the boiler. Sweated the fittings and the zone valve and connectors. Coiled the 100 feet of red flex PVC into the sump and covered it with LR and hooked it into the fittings. Purged the system. Pressure tested. No Leaks!
So, then I took my Finnex Thermo controller, and with the male portion of an extension cord, plugged that into the "heater" outlet of the controller. Then crimped some female blade connectors onto the wires. "plugged" those connectors into the appropriate connections (coil @ 120 volts) on the relay. Then I ran the "thermostat" wire to the relay from the zone valve and crimped connectors onto those and plugged them into the "control" side of the relay to act as a "Zone" thermostat. So now, in fact the thermo controller is controlling a zone on my oil home heating system.
My tank now has less variation in temp than with the 500 watt heater connected to the controller. 80 min - 82 max over 3 weeks. My electric bill has gone down considerably. Cannot determine exactly how much.
YMMV..
Any questions?
Pics:
Heater relay:
Sump: (nicely heated!)
Controller (a bit modified!)
Copper to PVC transition:
I removed my 500 watt heater plus one of the two 250 watt backups and replaced the main heat source for the tank (300 gallons total) with a system I designed as an additional zone off of my forced hot water oil-fired home heating system.
My main concern was the heat exchanger. Copper was out, so I got some flexible PVC tubing (red) from Lowe's (100 ft - approx $25.00) and some 90 degree 3/4 fittings. I figured that the PVC is not as conductive as copper so I "guessed" at 100 feet to submerge as the heat exchanger. No copper can touch the saltwater. I got a zone valve ($80 at Lowe's) a project box I had planned for my ATO, 1-120 volt coil solenoid, some connectors, wires of various purposes, leftover 3/4" M copper pipe, fittings, other small stuff and I was on my way. I plumbed the feed an return to the basement sump room and to the 150 gallon sump from the boiler. Sweated the fittings and the zone valve and connectors. Coiled the 100 feet of red flex PVC into the sump and covered it with LR and hooked it into the fittings. Purged the system. Pressure tested. No Leaks!
So, then I took my Finnex Thermo controller, and with the male portion of an extension cord, plugged that into the "heater" outlet of the controller. Then crimped some female blade connectors onto the wires. "plugged" those connectors into the appropriate connections (coil @ 120 volts) on the relay. Then I ran the "thermostat" wire to the relay from the zone valve and crimped connectors onto those and plugged them into the "control" side of the relay to act as a "Zone" thermostat. So now, in fact the thermo controller is controlling a zone on my oil home heating system.
My tank now has less variation in temp than with the 500 watt heater connected to the controller. 80 min - 82 max over 3 weeks. My electric bill has gone down considerably. Cannot determine exactly how much.
YMMV..
Any questions?
Pics:
Heater relay:
Sump: (nicely heated!)
Controller (a bit modified!)
Copper to PVC transition: