Copy below from a
@rod_vw post a few years back regarding GC heater options - looks like code 637UB is the one you have fitted.
CODE: 637UA | PR-Nr. 7VF | Cab interior MY2022 Programmable air parking heater, with radio remote control and additional auxiliary heat.
DESCRIPTION
The fuel-powered independent air heater can be operated and programmed via an auxiliary control unit in the roof module and a remote control. The heating power is 3.5 kW, which can be used as an auxiliary or independent heating function. The max. heating duration is 48 hours. The floor vent provides heated air in the centre between the front seats. The independent air heater is supplemented by a fuel-powered auxiliary heater (5 kW). The auxiliary heater is activated/deactivated using the touch-sensitive display of the radio or navigation system (Media Van Advanced/Media Van Navigation). The range of the radio remote control is several hundred metres for a full battery. Obstacles between the radio remote control and the vehicle, poor weather conditions and a depleting battery reduce the range considerably in some cases. The distance between the radio remote control and the vehicle must be at least 2 metres. The optimum range is achieved when the radio remote control is held with the antenna (1) pointing straight up. The check lamp (2) gives the user various information when a button is pressed: - If the check lamp flashes green irregularly for around 4 seconds, the independent heating is blocked. The fuel tank is almost empty, the voltage of the vehicle battery is too low or there is a fault. This can be rectified by refuelling and driving for long enough to charge the vehicle battery. - If the check lamp flashes red or green regularly for around 4 seconds, the signal has not been received. This can be rectified by reducing the distance from the vehicle. - If the battery in the radio remote control is low, the check lamp lights up orange for around 2 seconds and then lights up (switch-on or switch-off signal received) or flashes (switch-on or switch-off signal not received) red or green. The battery should be replaced as the range may be reduced.
Customer benefit.
The fuel-powered independent air heater ensures that the vehicle is heated when stationary with the engine switched off and also provides a ventilation function. The independent air heater can thus also be used to heat the interior more quickly and to maintain the temperatures. Ideal for vehicles that are stationary for long periods (for example construction site vehicles). The remote control makes operation more convenient. The independent air heater can also be used to heat the cargo compartment of a box-type van when the cab is separate. The fuel-powered auxiliary heater (5 kW) is only switched on during engine operation to support the standard heater.
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CODE: 637UB | PR-Nr. 7VL | Cab interior MY2022 Water heater with programmable parking heater function and radio remote control.
DESCRIPTION
The additional water heater with 5 kW heating capacity has an auxiliary heating and auxiliary heating function that can be programmed and controlled via a radio remote control. The control panel for auxiliary heaters and heat exchangers is located at the top in the middle of the roof gallery. Range: a few hundred meters if the radio remote control with antenna is held vertically upwards (can be significantly reduced by obstacles between the radio remote control and the vehicle, bad weather conditions and a weak button cell) Back information from the indicator light: - If the green flashes irregularly for 4 seconds, the auxiliary heater is blocked. The cause for this can either be an empty fuel tank, insufficient voltage in the vehicle battery or an existing fault. This can be remedied by refueling and driving long enough to charge the vehicle battery. - Red or green flashing steadily for 4 seconds, the signal was not received. This can be remedied by reducing the distance to the vehicle. - Orange light for 2 seconds: weak button cell. Then it lights up (switch-on or switch-off signal received) or flashes (switch-on or switch-off signal not received) red or green. In this case the button cell should be replaced as the range can be reduced.
Customer benefit.
The auxiliary water heater supports the on-board heater so that higher temperatures in the interior can be reached more quickly and these can be maintained. Using a programmable independent heater function, the auxiliary water heater heats the vehicle before the start of a trip (for example to defrost the windows) and when it is stationary.
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CODE: 637UC | PR-Nr. 7VM | Cab interior MY2022 Programmable air parking heater with radio remote control.
DESCRIPTION
The fuel-operated air heater can be operated and programmed via an additional control unit in the control panel and a remote control. The heating power is 3.5 kW and the max. Heating time 48 hours. The floor vent provides heated air in the middle between the front seats. The control panel for the auxiliary heater is located in the middle of the roof gallery. Range: a few hundred meters if the radio remote control with antenna is held vertically upwards (can be significantly reduced by obstacles between the radio remote control and the vehicle, bad weather conditions and a weak button cell) Back information from the indicator light: - If the green flashes irregularly for 4 seconds, the auxiliary heater is blocked. The cause for this can either be an empty fuel tank, insufficient voltage in the vehicle battery or an existing fault. This can be remedied by refueling and driving long enough to charge the vehicle battery. - Red or green flashing steadily for 4 seconds, the signal was not received. This can be remedied by reducing the distance to the vehicle. - Orange light for 2 seconds: weak button cell. Then it lights up (switch-on or switch-off signal received) or flashes (switch-on or switch-off signal not received) red or green. In this case the button cell should be replaced as the range can be reduced.
Customer benefit.
The fuel-powered independent air heater ensures that the vehicle is heated when stationary with the engine switched off and also provides a ventilation function. It can also be used to heat the interior more quickly and to maintain the temperatures. Ideal for vehicles that are stationary for long periods, for example construction site vehicles.
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CODE: 637UE | PR-Nr. 9M4 | Cab interior MY2022 Programmable air parking heater and water heater with radio remote control.
DESCRIPTION
The fuel-powered independent air heater can be operated and programmed via an auxiliary control unit in the roof module. The heating power is 3.5 kW, which can be used as an independent heating function. The max. heating duration is 48 hours. The floor vent provides heated air in the centre between the front seats. The independent air heater is supplemented with a fuel-powered auxiliary water heater (5 kW) which functions as auxiliary heating and independent heating and can be operated and programmed via a radio remote control. The range of the radio remote control is several hundred metres for a full battery. Obstacles between the radio remote control and the vehicle, poor weather conditions and a depleting battery reduce the range considerably in some cases. The distance between the radio remote control and the vehicle must be at least 2 metres. The optimum range is achieved when the radio remote control is held with the antenna (1) pointing straight up. The check lamp (2) provides the user with various feedback information when a button is pressed. - If the check lamp flashes green irregularly for around 4 seconds, the independent heating is blocked. The fuel tank is almost empty, the voltage of the vehicle battery is too low or there is a fault. This can be rectified by refuelling and driving for long enough to charge the vehicle battery. - If the check lamp flashes red or green regularly for around 4 seconds, the signal has not been received. This can be rectified by reducing the distance from the vehicle. - If the battery in the radio remote control is low, the check lamp lights up orange for around 2 seconds and then lights up (switch-on or - switch-off signal received) or flashes (switch-on or switch-off signal not received) red or green. The battery should be replaced as the range may be reduced.
Customer benefit.
The independent air heater ensures that the vehicle is heated when stationary with the engine switched off and also provides a ventilation function. It can also be used to heat the interior more quickly and to maintain the temperatures. Ideal for vehicles that are stationary for long periods, for example construction site vehicles. The auxiliary water heater acts as an auxiliary heater and, using the programmable independent heater function, heats the vehicle before the start of a trip (for example to defrost the windows) and when it is stationary. The independent heating functions of the independent air heater and the auxiliary water heater are separate from each other. This means that in vehicles with a closed partition wall there are separately programmable independent heaters for the cab and cargo compartment.
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CODE: 637UF | PR-Nr. 9M5 | Cab interior MY2022 Auxiliary heater
DESCRIPTION
An auxiliary water heater is installed that is powered by diesel fuel and functions as an auxiliary heater with a heating power of 5 kW. The fuel-powered auxiliary heater is only switched on during engine operation to support the standard heater.
Customer benefit.
The auxiliary water heater supports the on-board heater so that higher temperatures in the interior can be reached more quickly and these can be maintained at a constant level. At the same time, the operating temperature of the coolant is reached more quickly, which protects the engine. The cab and the cargo compartment/passenger area can be heated with or without a partition wall.
