Photo Gallery

Install#1 before upgrade:

Oil furnace + heat-pump (dual– heat)

Install #1 after upgrade:

3-Flex tri–heat installed

Install#1 after upgrade: Close-up 3-flex and plenum heater and 3-Flex controller.

Install#1 before upgrade: close-up dual-heat fossil fuel kit.

dual-heat to tri-heat coversion pictures.

Install#2 before upgrade: Oil furnace + heat-pump dual– heat and old oil fired hot water boiler.

Install #2 after upgrade: tri–heat

and new insulated electric hot water tank

3-flex and plenum heater

Furnace fresh air intake pipe

Install#3 before upgrade: Oil furnace + heat-pump dual– heat.

Bottom mounted plenum heater

3-Flex control unit

Modified hot air intake

Install #3 after upgrade: 3-Flex tri–heat installed.

Bottom entry plenum heater with separate pressure switch. Some hot air intake pipes needed re-routing

Install #4 after upgrade: fully installed

Install #4 after upgrade:

3-Flex tri–heat installed 1 hot air intake pipes needed re-routing. 3-flex and plenum heater without cover.

Hoyme motorized fresh air intake damper.

By building safety code, combustion furnaces require a separate fresh air intake. To prevent unwanted cold air infiltration a motorized fresh air damper controlled by 3-flex allows outside air into the house only when the furnace is on.

Electric plenum heater.

Front/top view of a typical custom built multi-stage electric plenum heater controlled by 3-flex for installation in the vertical stack on top of the indoor heat pump coil as shown in install #1 pictures.

New electric hot water heater

3-Flex control

Plenum heater with cover installed

3-Flex control no cover

Horizontal duct mounted plenum heater (no cover)

Separate pressure switch