Additional Components - Truma Combi Service Handbook

Component Glossary
14. Stainless Steel Water Container : 2.64gal (10 liter) water
container made of V4A stainless steel. The Water Container
surrounds the Air Heat Exchanger and absorbs heat from the Gas
Burner or Electric Heating Elements (Plus models only) to heat the
water for the domestic water supply. The Combi does NOT feature
instant or on demand water heating technology and thus has a
recovery time, like a traditional water heater, to reach the desired
water temperature setpoint.
15. Warm Water Connection Tube : 12mm connection for Warm
Water Connection with Aeration Valve (34020-00178) to hot water
outlet. Aeration Valve features a gravity fed check valve before the
connection of a clear air tube, with the purpose of ensuring all 2.64
gal (10 liters) are drained from the Water Container when the
Drain Valve is opened. Warm Water Connection with Aeration
Valve must be installed so that the hot water plumbing flows in a
vertical direction while the Aeration Valve is positioned in a
horizontal configuration (see component "K")
16. Cold Water Connection Tube : 12mm connection for cold water
inlet.
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Additional Components

A
D. Water Temperature Switch (All models) : N.C. thermal safety
switch that opens it's contacts to end the ignition sequence if it
senses temperatures above 185°F (85°C).
E. Water Temperature Switch (Plus models only) : N.C. manually
resettable safety switch that opens it's contacts to end the
ignition sequence if it senses temperatures above 185°F (85°C).
F. Water Temperature Sensor(s) (Not pictured) : NTC
thermistors that informs the PCB of the temperature within the
Water Container by converting temperature to resistance.
17. Room Air Temperature Sensor : NTC thermistor that tells the Combi the
ambient temperature within the living space by converting temperature to
resistance Ω. Connected to the Combi PCB by a wiring harness. At 77⁰F (25⁰C),
the Room Air Temperature Sensor should register approximately 10K Ω. X10
and X11 wire harness connection points at Combi PCB from RTS are not
polarity sensitive.
18. Casing HDF-Therm : Insulation jacket of the Truma Combi
A. Air Temperature Switch(es) : N.C safety switch located in the
Air Distribution Chamber that opens it's contacts to end the
ignition sequence if it senses temperatures above 374°F (190°C).
B. Air Temperature Sensor : NTC thermistor that informs the PCB
of the temperature within the Air Distribution Chamber by
converting temperature to resistance.
C. Combustion Air Temperature Sensor (Not pictured) : NTC
thermistor that informs the PCB of the temperature within the
Combustion Chamber by converting temperature to resistance.
B
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14
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E
D