OPERATION
SECTION 5
When properly installed and adjusted, the heater will require minimal attention. Should it
become necessary to completely drain the heater, close the cold water inlet valve and
open a hot water tap to allow air to enter the system. Fit a suitable hose to the drain
cock and open.
Whenever the heater is filled with cold water, condensation may form on the storage
vessel surfaces when the burner is lit. This is normal and will disappear when the heater
warms up.
The thermostats fitted to heater models OFS25, OFS29, OFS63 & OFS90 have a built in
high limit thermostats. In the case of dangerous water temperatures the fuel supply will
be automatically shut off. The reason for such high temperature must be corrected before
the heater is relit.
The two control thermostats where applicable (OFS108 & OFS163) should both be set to
the same operating temperatures. This will ensure stacking does not occur and will avoid
high water temperatures when small amounts of water are drawn off during peak times
of use.
23
