Amtrol BoilerMate Top Down - Manual (Page 29)

A diminished temperature difference between
the boiler water entering and leaving the heat
exchanger coil may indicate heat exchanger scale
buildup. Water treatment equipment and proper
maintenance will help to avoid this problem. To
clean a scaled heat exchanger coil proceed as
follows:
1. Shut off the cold water supply to the
BoilerMate ® .
2. Make a note of the temperature control setting
on the BoilerMate ® , then turn the unit off.
3. Relieve the water pressure in the tank by
opening a hot water faucet. This will reduce the
risk of scalding injury.
4. Remove the relief valve from the top of the
BoilerMate ® , taking care to avoid contact with
the hot water, which may drain out of the
plumbing.
5. Drain the BoilerMate ® until the water within the
tank is even with the top of the heat exchanger
- approximately 15 gallons for 41-gallons units
and 5 gallons for 26-gallon units.
Do not over-drain the tank.
Improper thermostatic control
could result during Step 6 and lead to damage to
the BoilerMate
® .
6. Using a funnel, pour one gallon of non-
toxic commercial phosphoric acid solution
(commercial icemaking cleaning solution) into
the water tank through the top opening. Be
sure that the manufacturer’s directions and
warnings are followed.
-29-
15. CLEANING THE BOILERMATE ®
HEAT EXCHANGER COIL
7. Set the temperature control to its highest setting and
operate the unit until the control is satisfied. Note:
Boiler may cycle on its high limit several times during
this period. If the tank temperature setting has not been
satisfied after 45 minutes of boiler operation, turn the
BoilerMate
® control off to stop boiler operation.
8. Allow heated solution to set in tank for 30 minutes,
then drain tank completely using fitting and hose, as
required.
9. Fill water tank with fresh, cold, conditioned water and
drained completely at least two times or until drained
water runs clear.
10. Reinstall the safety relief valve.
11. Open the cold water supply and fill the tank with water.
Purge plumbing by operating all hot and cold water
fixtures in the building.
12. Return the control to the setting noted in Step 2 and
verify that the unit is functioning properly.
As an alternative to the above, the teat exchange may
be removed from the BoilerMate
® and cleaned. A new
gasket must be installed whenever the heat exchanger
is removed.