LAARS Mighty Therm2 MT2P (Sizes 500–2000 MBTU/h) - Install and Operating Manual - Manual (Page 20)

LAARS Heating Systems Page 20
kPa) and the CO
2
is adjusted to 8.0% for Natural Gas
appliances or 9.2% for LP appliances. When using an
O
2
analyzer, the correct O
2
is 6.8% for both Natural Gas
and LP appliances.
Caution
Should any odor of gas be detected, or if the gas
burner does not appear to be functioning in a normal
manner, close main shutoff valve, do not shut off
switch, and contact your heating contractor, gas
company, or factory representative.
6.4 Shutting Down the MT2P
1. Switch off the main electrical disconnect switch.
2. Close all manual gas valves.
3. If freezing is anticipated, drain the MT2P and be
sure to also protect building piping from freezing.
This step to be performed by a qualified service
person.
6.5 Spring and Fall Operation
Stand-by Service
Turn the thermostat down to approximately 70°F
(21°C). This will prevent the pool and surrounding
ground from becoming chilled and permit the pool to be
raised to swimming temperature in a shorter length of
time. Do Not Operate below 60°F (16°C).
6.6 Winter Operation
Complete Shutdown
1. See Section 6.4
2. If the heater is not protected from freezing
temperatures, it should be completely drained
before the first frost. Drain the heater by
removing the plug at the end of the inlet/outlet
header casting. Also, remove the small plug at the
bottom of the pump housing. Do not replace either
plug until the time that refilling is desired. The
heater must be level for complete draining. When
compressed air is used to blow out lines, it is still
necessary to follow these directions. Because
of the potential for electrical power failure or
pump failure, freeze protection should never
be accomplished by operating the pool heater
and the filter pump. Either of those failures will
potentially allow a freeze up and cause damage to
the heater and the attached system.
3. Improper use of the heater: The Laars PNCP
pool heater is not designed for continuous use as
a “anti-freezing” device for pools. Operating the
heater at low water temperatures will damage the
heat exchanger.
6.7 To Restart the MT2P
If drained, follow Section 6.2 in this manual for
proper filling and purging.
1. Switch off the main electrical disconnect switch.
2. Close all manual gas valves.
3. WAIT FIVE (5) MINUTES.
4. Set the pool aquastat to its lowest setting.
5. Open all manual gas valves.
6. Reset all safety switches.
7. Set the temperature controller to the desired
temperature setting and switch on electrical
power.
8. Burner will go through a prepurge period and
ignitor warm-up period, followed by ignition.
6.8 Therapeutic Pools (Spas)
Therapeutic pools or “spa” pools are usually
piped and controlled so that very warm or hot water,
often with air injection, is forced at high velocity
into a confined area of a swimming pool or into a
small separate pool. For the purposes of this manual,
any application in which the water temperature is
maintained above 85°F (30°C) is considered a spa.
SPECIAL SET-UP AND OPERATING PROCEDURES
APPLY TO SPAS.
1. MT2P 1000 and larger should not be used for spas
due to their higher temperature rises.
2. To ensure that the spa inlet does not exceed 104°F
(40°C), the spa filter pump must circulate water at
the minimum flow rates shown in Table 8.
NOTE: Maximum Spa Temperature Is Assumed To Be
100°F (38°C).
3. Spas are excellent for relaxation, body-
conditioning and for arthritic and rheumatic
problems, but can be hazardous.
WARNING
The U.S. Consumer Product Safety Commission has
warned that elevated temperatures in spas and hot
tubs can be hazardous. Follow these “Safety Rules for
Hot Tubs:”
• Spa or hot tub water temperatures should never
exceed 104°F (40°C). A temperature of 100°F
(38°C) is considered safe for a healthy adult. Special
caution is suggested for young children.
• Drinking of alcoholic beverages before or during
hot tub use can cause drowsiness, which could
lead to unconsciousness and subsequently lead to
drowning.
• Pregnant women beware! Soaking in water above
102°F (39°C) can cause fetal damage during the first
three months of pregnancy (resulting in the birth of a
brain-damaged or deformed child). Pregnant women
should stick to the 100°F (38°C) maximum rule.
• Before entering the spa or hot tub, users should
check the water temperature with an accurate
HEATER MODEL MINIMUM FILTER
PUMP FLOW RATE
MT2P 500 240 GPM
MT2P 750 360 GPM
Table 8. Minimum Filter Pump Flow Rates For Spas.