DESCRIPTION AND PRINCIPLE OF OPERATION
The outside casing of the EWH is made of impact-resistant plastic. Inner tanks
have a special bio-glass-porcelain coating reliably protecting the inner surface against
chemical corrosion. The space between the outside casing and the inner tanks is filled
with polyurethane foam - a modern, ecologically clean thermal insulation, which has the
best heat-saving characteristics. These models have two screwed nozzles: for inlet of
cold water (Figure 1, p. 3) with a blue ring and for outlet of hot water (Figure 1, p. 2) —
with a red ring, and equipped with an additional drain connection (closed with metal plug
button) for draining the water and flushing the inner tank (Figure 1, p. 17). The control
panel, in all models, is on the front side of the EWH (Fig. 1, p. 16).
Tubular electric heater (TEH), thermostat and thermal switch sensors are mounted
on the removable flange. TEH is used to heat water and is controlled by thermostat which
has smooth temperature regulation adjustment up to +75°С. All models are controlled
with electronic monitoring panel. Electronics maintain automatically water temperature
at the level set by the user. The thermostat is used for protecting against EWH overheat-
ing, which disconnects TEH from power supply when water temperature exceeds 95°С.
(Fig. 3).
Safety valve (Fig. 1, p. 5) operates as the check valve, ensuring protection of the
water ingress from the water heater into the sewage system in case of pressure drop in
the sewage system and in case of pressure rise in the tank at high water heating, as well
as the functions of the safety valve, releasing overpressure in the tank at high water
heating. During water heater operation water may leak out of the exhaust outlet pipe of
the safety valve to relieve excessive pressure, which is made for the purpose of water
heater safety. This outlet pipe shall remain open to the atmosphere and be installed
constantly down and in a non-freezing environment.
Drainage of water from the safety valve (Fig. 1, p. 14) exhaust pipe into the drain
shall be provided with installation of the corresponding EWH drainage (Fig. 1, p. 6).
It is required regularly (at least once a month) to discharge a small amount of water
through the exhaust pipe of the safety valve into the drain to remove lime deposits and
to test the operating functionality of the valve. Handle (Fig. 1, p. 15) is intended to open
the valve. It is necessary to control when operating water heater this handle to be in
position closing water draining from the tank.
