autoterm combiBOIL Hot Water Boiler User Manual

: June 13, 2024
: Autoterm

Table of Contents

autoterm combiBOIL Hot Water Boiler
Product Information
Product Usage Instructions
FEATURES
DIMENSIONS
combiBOIL can generate hot water in three different ways
CONNECTION INSTRUCTIONS
Heating a second water loop
INSTALLATION AND OPERATION
combiBOIL overview
Service & Warranty
References
Read User Manual Online (PDF format)
Download This Manual (PDF format)

autoterm combiBOIL Hot Water Boiler

autoterm-combiBOIL-Hot-Water-Boiler-PRODUCT

Product Information

The AUTOTERM combiBOIL is a hot water boiler designed and engineered in Germany. This product manual provides detailed information about the installation, features, and various functions of the boiler.

Features

Can generate hot water in three different ways:

1. Using an electric heating element
2. Through warm air from an air parking heater
3. Via connection to the motor coolant circuit

Dimensions The dimensions of the combiBOIL are not provided in the user manual. Please refer to the product packaging or contact your dealer for accurate dimensions.

Product Usage Instructions

Using Electric Heating Element (Connection E) The electric heating element can be operated from the onboard supply at 12/24V or connected to the 230/110V shore power network. It is important to note that there is no thermostat function or safety shutdown integrated into the heating element due to space constraints.

To operate the electric heating element:

Ensure the boiler is not dry before operating the heating element. Operating the heating element when the boiler is dry may cause damage.
Shutdown at the desired target temperature or overheating must be implemented externally, e.g., with an external thermostat module.
Operate the electric heating element only when hot water is needed. Continuous operation is not recommended.
Ensure adequate fusing and use cable sizes according to local regulations.

Using Hot Air from Heater (Connection A) The warm air leaving the heater can be directed into the boiler through a 90mm connection and an air-to-water heat exchanger. The inlet and outlet are identical, allowing either side to be used as an inlet.

The heating time depends on factors such as the starting temperature of the water in the boiler, intake air temperature of the heater, and flow speed.

Coolant Circuit (Connection F) The boiler can be integrated into the motor’s coolant circuit for various purposes:

Coolant circuit heats domestic water
The boiler preheats the coolant circuit (engine)
Heating a second water loop

The heat energy supplied to the boiler through the electric heating element or warm air can be transferred to a second water loop via a circulation pump. This can be used for underfloor heating or a towel-drying radiator. Consult your dealer for advice on regulating the flow temperature and the need for a mixer valve.

Congratulations on your purchase of this combiBOIL hot water boiler!

This product manual contains detailed information about the installation, features, and various functions of the boiler. Please read the manual carefully before starting the installation and use of the device.

FEATURES

The boiler body is made of corrosion-resistant 316L stainless steel for durability and longevity
The impact-resistant and resilient outer casing
Insulation with closed-cell polyurethane foam to minimize heat loss
Highly efficient coolant-water heat exchanger made of 316L stainless steel
Electric heating element made of INCOLOY superalloy
Air-water heat exchanger with low flow resistance and high heat transfer
Cold water inlet
Safety valve with a preset relief pressure of 3 bar.
Hot water outlet
Rotatable stainless steel mounting brackets for secure installation in various positions
Drain valve for emptying the boiler, e.g.,during winter storage
A built-in check valve in the domestic water circuit
G1/2″ standard screw connections for maximum installation flexibility
Built-in thermostat in versions with 120/230Vheating elements
Optional available thermostat module for 12/24V
Monitored and controlled through Autoterm
Comfort Boiler Control heating control panel

DIMENSIONS

autoterm-combiBOIL-Hot-Water-Boiler-
FIG-1

combiBOIL can generate hot water in three different ways

autoterm-
combiBOIL-Hot-Water-Boiler-FIG-2

The applications are detailed as follows:

Using Electric Heating Element / Connection E (electrical)

The electric heating element can be operated from the onboard supply at 12/24V or connected to the 230/110V shore power network. The heating time depends on the initial water temperature in the boiler.

Operate the electric heating element only when hot water is actually needed. Thus, continuous operation (continuous supply voltage to the heating element) is not recommended.

The electric heating element must not be operated when the boiler is dry. In such a case, no liability can be assumed for damages.

Ensure adequate fusing. The cable sizes to be used for the installation may vary depending on the operating voltage and should be dimensioned according to local regulations.

CONNECTION INSTRUCTIONS

12/24V (DC/Direct Current): Due to space constraints, there is no thermostat function or safety shutdown integrated into the heating element! Shutdown at the desired target temperature or overheating MUST be implemented externally (e.g., with an external thermostat module)
120/230V (AC/Alternating Current): Pay attention to proper wiring of the ground/earth contact. If necessary, certified technicians should be consulted. Furthermore, the maximum heating temperature can be set using the rotary knob under the black protective cap. Here, a shutdown temperature of 0 to 65°C can be set. The hysteresis is fixed at approximately 9K. An internal additional safety threshold will shut power supply off in case of malfunction – independently and no later than at 90°C. If this happens, this thermal fuse must be manually reset (reset button).

No responsibility is accepted for the accuracy of this information.

Using Hot Air from Heater / Connection A (Air)

The warm air leaving the heater can be directed into the boiler through a 90mm connection and an air-to-water heat exchanger. The inlet and outlet are identical, allowing either side to be used as inlet.
The heating time depends on factors like the starting temperature (of the water) in the boiler, as well as the intake air temperature of the heater and flow speed.

It‘s important to ensure that the temperature in the boiler does not exceed 85°C. Therefore, the heater should be shut down in time. With the Autoterm Comfort Boiler Control heater control panel, this can be done automatically, eliminating the need for manually operated control flaps. Only in cases of extremely high demand for warm air (very low temperatures with poorly insulated cabin), a control flap might still be useful. Without using Comfort Boiler Control, warm air should be redirected away from the boiler using a control flap or other suitable control methods to prevent overheating.

Coolant Circuit / Connection F (Flow)

The boiler can be integrated into the motor‘s coolant circuit to either heat domestic water or a second water loop. Vice versa, the engine can be preheated to facilitate a more gentle start (not suitable for extremely cold Arctic temperatures). The integration options into the coolant circuit are as follows:

Coolant circuit heats domestic water

The coolant circuit is connected to the boiler, and while driving, it heats domestic water for showering, etc. Note that the temperatures in the coolant circuit can exceed 100°C due to pressure. This could lead to boiling of the domestic water in the boiler, resulting in dangerous steam generation and possibly triggering the safety valve. This should be avoided at all costs. Use a valve in the coolant circuit and/or disable the circulation pump to prevent the boiler from heating beyond 85°C.

The boiler preheats the coolant circuit (engine)

Reverse of the above function. By connecting the boiler to a 230V/110V power source or using warm air from the cabin heater, the engine coolant circuit can be preheated. This prevents freezing of the engine in low temperatures orallows a gentle start under such conditions. The effectiveness of this method depends on ambient temperatures and the engines’ size. Inarctic conditions, the power required to significantly raise the temperature of a large engine is much higher than the heat input into a hot water boiler. In this case, a combination with an Autoterm Flow heater might be advisable.

Heating a second water loop

The heat energy supplied to the boiler through the electric heating element or warm air can be transferred to a second water loop via a circulation pump. This could be used for underfloor heating or a towel-drying radiator.
The connection of both water loops (with the coolant circuit heating the second water loop) is also possible. Like mentioned above, attention must be paid to regulating the flow temperature; a mixer valve may be necessary. Please consult your dealer for advice.

INSTALLATION AND OPERATION

Caution: combiBOIL can heat water to up to 85°C (depending on the heating method). Direct un-mixed of domestic water can result in serious burns. Use a scald protection/ pre-mixing valve (recommended!) or set an appropriate target temperature on the Comfort Boiler Control panel.

The boiler can be mounted on the floor, wall, or inclined surfaces. When choosing the installation position, ensure that the drain is located at the lowest point.

The mountings allow a flexible installation and can be adjusted as the boiler is rotatable in the brackets. Make sure the boiler is mounted horizontally for proper operation.
All water connections B on the boiler conform to the G 1/2” standard.
To prevent leaks, all water connections should be sealed with appropriate sanitary sealant (e.g., thread sealing tape).
The cold water inlet should be limited to 1.5 bar using a pressure reducer (not included). The integrated safety valve with a 10 mm hose connection (preset to a relief pressure of 3 bar) must be connected to a hose leading outside and be functional at all times to prevent damage to the boiler or water damage in the vehicle due to excessive water pressure.If using a heater with 60mm warm air outlet (Autoterm Air 2D), an adapter for transitioning to the 90mm inlet on the boiler is available.

The installation location must be frost-resistant or kept frost-free through appropriate heating measures. During periods of non-heated cold temperatures (winter storage), the boiler should be drained through the drain valve.
The safety valve should not be used for draining. However, both valves can share a combined outlet, eliminating the need for multiple openings through the floor.

Caution: While this boiler is produced with the utmost care and highest standards, the presence of residues on surfaces that come into contact with water cannot be ruled out. Therefore, before regular use, rinse the boiler with clean drinking water at least once to prevent contamination of drinking or domestic water.

Hot water system with combiBOIL Hot water system with combiBOIL

boiler
heater
control panel
steel flex line
thermostatic mixing valve
pressure regulator
freshwater tank
pressure water pump + accumulator tank
water filter
water tap/shower

combiBOIL overview

A drain
B water connections
C mountings
D integrated safety valve
E 90mm inlet
F coolant heat exchanger

autoterm-combiBOIL-Hot-Water-Boiler-FIG-8

The Autoterm Comfort Boiler Control panel is specially designed to combine the functions of Autoterm heaters and combiBOIL hot water boilers. All heating control options remain available.