Controlled Energy and Bosch Tankless Heaters - CEC

Controlled Energy Corporation - CEC
Controlled Energy Corp., 340 Mad River Park, Waitsfield, VT 05673

Controlled Energy was a tankless water heater pioneering company bringing the tankless technology to the USA.  From their Vermont mountain location, CEC distributed their Tankless Heaters throughout the USA through reps and distributors.  In about 2004 CEC closed down. Anderson-Bolds was the Ohio CEC rep.

CEC bought heaters from Bosch, Takagi, Ariston, Red Wing, Eemax and others.  They named their gas heaters AquaStars and the Electric heaters were called PowerStars and PowerStreams.

AQUA STAR Models were AQ 38B, AQ 125, AQ 125B, AQ 125X, AQ 125HX, 125FX, 240FX, 250SX

Spare and repair Parts for some of these heaters can be purchased HERE.

The PowerStar Heaters were electric point of use and whole house heaters.  

These are the Power Stream heaters and they are still available:
RP1  9.5 kw, 220/240 volts  40 amps
RP2  6.0 kw, 277 volts  22 amps
RP3  3.2 kw, 120 volts  30 amps
RP7  7.2 kw, 220/240 volts  30 amps
RP9  9.5 kw, 277 volts  35 amps
RP12  12kw, 220/240 volts  50 amps

They became know as the AE3.4 (RP3), AE7.2 (RP7), AE9.5 (RP1) and AE12 (RP12).  

Their are two Power Star models.

AE115   17kw, 220/240 volts  80 amps

The AE115 is normally used in the southern part of the country where ground water is always above 60 degrees F year round.  The heater requires 2 x 40 amp double breakers.  It has an adjustment knob to limit the outlet temperature.  Only one shower should be operated at a time.  Homes with two showers should take turns.  Flow rate of the water is the determining factor of the outlet temperature.  the higher the flow rate the lower the outlet temperature.  At a flow rate of 2.5 gallons per minute the heater with change or raise the water temperature about 45 degrees.  A 150 amp panel minimum is required for installation.

AE125   27kw, 220/240 volts  120 amps

The AE115 can be used throughout the country.  The heater requires 3 x 40 amp double breakers.  It has an adjustment knob to limit the outlet temperature.  Only one shower should be operated at a time.  Homes with two showers should take turns. If the ground water is above 70, two showers may possible be used simultaneously.  Flow rate of the water is the determining factor of the outlet temperature.  the higher the flow rate the lower the outlet temperature.  At a flow rate of 2.5 gallons per minute the heater with change or raise the water temperature about 65 degrees.  A 200 amp panel minimum is required for installation.

The Gas AquaStar heaters are now all made by Bosch Thermotechnology.

Most of the "retail" heaters are no longer manufactured.  

You can try GPTS to see of any are still available.

Bosch makes these now for wholesalers and they need to be properly installed.

The most critical component to a gas tankless water heaters is proper installation.

Tankless heaters are NOT drop in replacements for Tank heaters.  The heaters below range fro 74,000 BTU to 225,000 BTU with Stainless Steel vent, PVC vent, B-Vent vent, and outdoor units that do not require a vent.  Go here for your Z-Flex Stainless Steel vent needs.

Bosch Therm C 1210ESC-NG (Natural Gas) tankless water heater with secondary condensing heat exchanger

225,000 BTUs and up to 180 degrees F, Electronic Ignition, PVC exhaust.  Available in LP (propane) too.

Bosch Therm C 1210ES-NG (Natural Gas) tankless water heater with secondary condensing heat exchanger

225,000 BTUs and up to 140 degrees F, Electronic Ignition, PVC exhaust.  Available in LP (propane) too.

Bosch Therm C 1050ES-NG (Natural Gas) tankless water heater with secondary condensing heat exchanger

199,000 BTUs and up to 140 degrees F, Electronic Ignition, PVC exhaust.  Available in LP (propane) too.

Bosch Therm C 950ES-NG (Natural Gas) tankless water heater with secondary condensing heat exchanger

175,000 BTUs and up to 140 degrees F, Electronic Ignition, PVC exhaust.  Available in LP (propane) too.


Bosch Integra 500-NG (Natural Gas) tankless water heater with secondary condensing heat exchanger

199,000 BTUs and up to 140 degrees F, Electronic Ignition, PVC exhaust.  Available in LP (propane) too.


Bosch C 800ES-NG (Natural Gas) tankless water heater with secondary condensing heat exchanger

199,000 BTUs and up to 140 degrees F, Electronic Ignition, PVC exhaust.  Available in LP (propane) too.

Bosch Therm 940ES-NG (Natural Gas) whole-house tankless water heater

199,000 BTUs and up to 140 degrees F, Electronic Ignition, Stainless Steel exhaust.  Available in LP (propane) too.


Bosch Therm 940ESO-NG (Natural Gas) whole-house outdoor tankless water heater

199,000 BTUs and up to 140 degrees F, Electronic Ignition.  Available in LP (propane) too.

Bosch ProTankless 715ES-NG (Natural Gas) whole-house tankless water heater

199,000 BTUs and up to 140 degrees F, Electronic Ignition, Stainless Steel exhaust.  Available in LP (propane) too.

Bosch Therm 830ES-NG (Natural Gas) whole-house tankless water heater

175,000 BTUs and up to 140 degrees F, Electronic Ignition, Stainless Steel exhaust.  Available in LP (propane) too.

Bosch Evolution 500-NG (Natural Gas) whole-house tankless water heater

199,000 BTUs and up to 140 degrees F, Electronic Ignition, Stainless Steel exhaust.  Available in LP (propane) too.

Bosch ProTankless 425EF-NG (Natural Gas) whole-house tankless water heater

130,000 BTUs, Electronic Ignition, Side-Wall Vent Only.  Available in LP (propane) too.

Bosch Therm 520HN-NG (Natural Gas) whole-house tankless water heater

117,000 BTUs, Hydro Ignition, B-Vent exhaust.  Available in LP (propane) too.

Bosch ProTankless 425HN-NG (Natural Gas) whole-house tankless water heater

117,000 BTUs, Hydro Ignition, B-Vent exhaust.  Available in LP (propane) too.

Bosch Therm 330PN-NG (Natural Gas) Tankless Water heater

74,900 BTUs, Standing Pilot Light, B-Vent exhaust.  Available in LP (propane) too.

Bosch Therm 660EF-NG (Natural Gas) whole-house tankless water heater

140,000 BTUs and up to 160 degrees F, Electronic Ignition, Stainless Steel exhaust.  Available in LP (propane) too.

Bosch Therm 660EFO-NG (Natural Gas) whole-house outdoor tankless water heater

140,000 BTUs and up to 160 degrees F, Electronic Ignition.  Available in LP (propane) too.


If you have any questions, please call Paul at 216-360-9800