Maintenance; High-Pressure Pump; Deliming; Cleaning The Heating Coil - Frank FH 711 DMP Operating Instructions Manual

6.

Maintenance

Maintenance and repair services may be carried out by qualified personnel.
6.1

High-pressure pump

Change the pump lubrication oil at intervals of approx. 200 operating hours, but at the lat-
est, after 2 months of operation. For lubrication only use branded oils of the SAE 90 quality.
To change the oil, remove the draining screw and drain the oil. Then put the oil draining
screw back into place and refill oil through the funnel until the upper mark on the dipstick is
reached. Properly dispose of the used oil. Between oil changes, regularly check the oil level;
the oil level must always be within the two marks on the dipstick. If necessary, fill up oil.
6.2

Deliming

If no soft or softened water is used, lime deposits will settle down in the heating coil.
Depending on the local water hardness, the heating coil must be delimed in regular intervals,
to protect the unit from damages. Do not wait until the pressure is too high and the safety
valve responds or the protective motor switch cuts the machine off. Deliming is carried out
as follows.
Set ON/OFF switch to position "0". Loosen joint of the suction hose on the water inlet tank
and connect to deliming hose (which is a 1/2" hose featuring a filter basket at one end and a
straight hose sleeve with 3/4" external thread at the other end) and direct outside. Turn the
knob of the dosing valve to position "0". Fully close the thermostat handwheel. Fill 16 litres of
50 °C hot water into a container and add 2 litres of deliming compound SP.
Caution! The deliming agent is corrosive.
Wear safety clothing.In case of skin contact, rinse with water immediately.
Insert deliming hose into the container, unscrew spray nozzle from the spray lance and place
into the container to allow the deliming solution to flow into the container. The deliming hose
filter must always be situated below the liquid level within the container. Turn on the machine.
The deliming process is complete when the liquid has stopped foaming. Turn off the ma-
chine.
Empty container, properly dispose of the deliming liquid. Fill 16 litres clear, cold water into the
container and add 0.5 litres alcaline cleaning agent. Reinsert deliming hose and spray lance
into the container. Turn on the machine and flush heating coil using the alcaline solution for
5 minutes. Turn off the machine, set ON/OFF switch to position "0". Reconnect suction hose
to the water inlet tank, clean and reassemble spray nozzle. Mount and lock hood.
6.3

Cleaning the heating coil

In our works the burner has been adjusted so that in normal operation a contamination of the
heating coil ist not probable. However, under special circumstances, there may be the pos-
sibility of a contaminated heating coil. Therefore a regular check of the heating coil condition
is required every 6 months.
The cleaning of the heating coil should be performed as follows:
Remove hood, remove burner from mounting plate and close burner flame tube.
Remove rear heating coil cover after loosening the 3 fastening screws. Tilt the machine sup-
porting the steering castor and clean heating coil using the cold high pressure jet.
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