17
If antifreeze is used in boiler water, check concen-
tration. Boiler water (including additives) must be
practically non-toxic, having toxicity rating or
class of 1, as listed in Clinical Toxicology of
Commercial Products. A maximum 50/50 mixture
of inhibited propylene glycol is recommended.
Follow antifreeze manufacturer’s instruction.
Do not use automotive, ethylene glycol or
petroleum-based antifreeze. Do not use
any undiluted antifreeze. This can cause
severe personal injury, death or substantial
property damage.
Water from opened drain valves, unions
and other connections may be extremely
hot. To avoid severe personal injury, death
or substantial property damage:
- Tighten all drain hose connections.
- Direct hot water away from all persons.
Draining Outer (Boiler Water) Tank
1. Disconnect power supply to water heater.
2. Close boiler water isolation valves between
boiler and water heater.
3. Connect hose to boiler water drain valve at
water heater. Open and drain water to a safe
place.
4. To speed draining procedure, loosen air vent
on top of tank.
5. When draining is complete, close drain valve
and retighten air vent.
Draining Inner (Domestic Water) Tank
(See Domestic Piping Fig. 4 page 9)
1. Disconnect power supply to water heater.
- If outer (boiler water) tank pressure is
greater than 15 psig, relieve boiler pres-
sure and close isolation valves before pro-
ceeding.
2. Close system supply isolation valve.
3. Connect a hose to domestic water drain valve
at cold water inlet. Hose should extend to
drain at floor level to allow siphoning of
domestic water tank.
4. Open hot water faucet at highest point above
heater.
5. Open domestic water drain valve to start
siphoning.
6. When draining is complete, close hot water
faucet and domestic water drain valve.
WARNING
WARNING
Water Heater Maintenance
