Carver Cascade MK 2


During periods of freezing weather, when the caravan is unheated, the Cascade 2 MUST be drained to prevent frost damage.

The drain plug which is on the outside of the flue cowl should be unscrewed to permit draining. When the end of the drain plug thread is reached the plug can be pulled out a small distance, yet still be retained in the thread and permit draining to occur. To allow the system and tank to drain effectively, open all hot and cold taps while the heater is still warm. Leave drain plug and taps open for AT LEAST 30 MINUTES, to ensure complete draining. If your system also includes a Crystal Water System, make sure that the pump is emptied of any water and unscrew the filter cartridge to permit it to drain.

To recommission the heater:- Close cold taps and the drain plug and reconnect the pump. Let the system fill with water until water flows steadily from the hot taps. About two gallons of water will be required. Once the hot taps are flowing freely close them and switch on the Cascade 2.

Operating Instructions

1) BEFORE SWITCHING ON make sure that water flows from the hot taps. This indicates that the water heater is full. Check that the gas and electrical supplies have been connected and turned on.
2) SWITCH THE WATER HEATER ON at the wall switch. The green light will come on and remain on. THE GREEN LIGHT indicates that the heater is operating satisfactorily and does not refer directly to the burner operation.
3) THE YELLOW AND GREEN LIGHTS on together show that the voltage of the power supply to the heater is too low. The heater is automatically switched off until the voltage is high enough.
4) THE RED AND GREEN LIGHTS on together show that the burner has failed to light in the 10 second ignition period. This is usually due to failure of the gas supply or, in the case of a new installation, air in the gas pipes. Switch off and on again, which resets the controller and initiates a new ignition sequence. To clear air from the gas lines, several repetitions may be required.
5) TEMPERATURE AND ADJUSTMENTS. The heater is supplied with the thermostat set at maximum (approx 68C). If the water at the taps is hotter that you want, the temperature may be adjusted as follows:-
a) Switch off heater at the controller and allow to cool for at least 10 minutes.
b) Remove cowl from outside of caravan (4 cross head screws).
c) Lift the flap and turn toothed wheel inside it. Each tooth is about 1 C.
d) Replace the cowl, making sure it locates firmly on the square aluminium flue nose. Switch on and check temperature after about hour.

This can not be done on newer modles.


Water Heaters (as with other gas appliances) should be switched off and gas cylinder valve(s) closed whilst caravan is in motion. General Description

The Cascade 2 is a storage water heater of 9 litre (2 gallon) capacity. It is installed through the wall of the caravan and from the outside only the balanced flue is visible.

All working parts are contained in a single unit which is easily removable from outside the caravan.

The Cascade 2 is operated from a remote wall switch which is mounted in a convenient position. The green and yellow lights together show that the voltage at the heater is too low and that the heater has automatically been switched off. The yellow light will go out and the heater will switch itself on again when the voltage is restored. The green and red lights together show that the heater has failed to light during its 10 second ignition period and has shut itself down. It can be reset by switching off and on again.

Temperature control is by a thermostat which is adjustable by means of a thumbwheel inside the cowl.

In use, hot water flows from the hot water outlet of the heater when cold water is pumped into the inlet. The outlet is positioned below the top of the heater tank to produce an air cap to accommodate thermal expansion.

The control system will maintain the water at the temperature selected by switching the burner on and off as required. The lights do not show whether the burner is alight or not.

The normal functions of the heater are backed up by two safety features. The first is a pressure relief valve which vents the tank contents into the cowl if the internal pressure rises above 3 bar (44p.s.i). The second is a fusible plug fitted in the heat exchanger behind the cowl. Should the temperature of the heater become too high, the plug will melt and vent steam and water onto the burner which will put it out, shutdown the heater down and show the red light. The heater may not then be used until the thermostat and fusible plug have been replaced.

In the event of a gas leak, search for it using soapy water. DO NOT USA A NAKED FLAME.
If unsuccessful, turn of the gas at the cylinder and seek professional assistance.

Water Supply Notes.

The Cascade Water Heater is suitable for installation into any existing caravan water system, whether manually or electrically pumped, with only the following precautions.

1. It must not be directly connected to mains water supply.

2. It must have a pumped cold water input pressure no exceeding 20 p.s.i (1.4 bar). A pressure of approximately 10 p.s.i (0.7 bar) is recommended. If you are in doubt as to the maximum pressure capability of your present pump, check with its manufacturer

3. If the pump is manually switched and is capable of delivering more than 20 p.s.i output pressure, an automatic pressure limiting switch should be incorporated into the pressurised cold water part of the system. Failure to observe these precautions will cause premature operation of the heater’s pressure relief valve and prevent use of the entire water system.

4. The use of a positive displacement pump controlled by a pressure switch with a large differential between switch on and switch off pressures can produce unacceptable temperature variations at a shower that is fed by mixer taps. If a shower facility is required a centrifugal pump controlled by switched taps or a Whale pressure switch is recommended.

5. We recommend the Carver Crystal water supply system which co-ordinates with the Cascade 2.

Electrical supply notes

The Cascade 2 water heater is designed to operate from a nominal 12v DC negative earth supply. This is usually provided in a caravan by a car type 12v battery.
The heater will continue to operate satisfactorily down to 10.5v to cater for reducing voltage as the battery becomes discharged. Below 10.5v the yellow light on the switch panel will illuminate and the heater will cease to operate until the voltage increases again. The yellow light may illuminate when the water pump is operating due to the high current consumption of the pump. This will cease when the pump stops. The yellow light may also illuminate when the heater is fed by very light gauge wire or when the caravan is fed from the car by an extension lead. In these cases the wire gauge must be increased to reduce the voltage drop. Low voltage may also be due to poor or corroded connections.
Both the positive and negative feeds to the wall switch are fused. Failure of the left hand (fused) fuse indicates a failure in the heater, failure of the right hand (negative) fuse indicates a problem in the earth bonding of the caravan itself.
There are no user serviceable parts within the electronic control box behind the burner. If the seal on this box is broken the guarantee is invalidated.

2. All electrical connections should be well made and insulated.