51
C. BACK BURN (FIRESTAR DISPLAYS
)
1. High temperature in burner auger area -
Everything but the burner auger will be disabled.
The burner auger will run for two minutes, pause
for 10 minutes, and continue as required. The Back
Burn alarm will not stop until the controller detects
that the temperature in the burner auger area has
dropped.
D. FREQUENT PUMP TROUBLE OR POOR
WATER CIRCULATION
1. Pump mounted incorrectly - The pump must be
mounted with the pump motor horizontal and the
junction box either on the side or on top (see Fig.
70).
Fig. 70
Junction Box
on bottom
Junction Box
on side
Junction Box
on top
Correct
Correct
Incorrect
2. Deposits in water lines/heat exchanger walls - If
water high in silica or other mineral content has
been used to fill the outdoor furnace, material
deposits may build up on the insides of the supply
and return lines and on the heat exchanger walls. If
this occurs, the system will need to be drained and
then cleaned using Sludge Conditioner (p/n 166).
The system must then be refilled with the proper
amount of MolyArmor 350 and good quality water
(softened water, if possible).
3. Water will not circulate - If the system has been
drained and refilled, or if the system has been
opened for any reason (e.g., replacement of pump,
adding heat exchangers, repairing a leak), air must
be purged from the system (see Filling System with
Water and Purging Air section).
4. Poor water quality - Water with high amounts of
solids, sand or dirt can cause frequent pump failure.
Use softened and/or filtered water.
E. BURNING AN EXCESSIVE AMOUNT OF
FUEL.
1. High volume water heating - High volume water
heating (e.g., car wash, swimming pool, etc.) will
require high fuel consumption.
2. Excessive heat loss - See items 8-12 of Furnace
Does Not Heat.
3. Supply and return line heat loss - If not using
ThermoPEX, supply and return lines buried in a
wet, low-lying area may cause a large heat loss that
will greatly increase the fuel consumption.
4. High heat demand - Concrete slabs (with radiant
heat) that are poorly insulated or are exposed to
water or cold outside temperatures will require
increased fuel consumption. Bringing a concrete
slab up to temperature the first time will take a
considerable amount of time and fuel; once warm,
fuel consumption will be reduced if the concrete
slab and building are insulated properly. The
following items will cause a high heat demand: poor
insulation, large amounts of glass windows/doors
(e.g., greenhouses), overhead doors, uninsulated
crawl spaces, outdoor air infiltration and air leaking
through foundation.
F. FUEL NOT BURNING PROPERLY
1. Poor fuel or out of fuel - See Fuel Quality and
Storage section for recommendations about fuel
types. Check firebox to see if fire is out. Add fuel as
necessary.
2. Combustion fan blocked or obstructed - Check the
combustion fan and air flow path for obstructions.
3. Outdoor furnace exhaust obstructed - Check
outdoor furnace exhaust for obstructions. To inspect
the heat exchangers, remove the chimney transition
cover on the back of the furnace and open the firebox
door. It will probably be necessary to kneel down at
the back of the furnace to look through each heat
exchanger passageway.
Section 10 - Troubleshooting
