Pressure Relief Valve - Suburban SW12D Installation And Operation Manual

PRESSURE RELIEF VALVE

T he tem perature and pressure relief valve is designed to open if the tem perature
of the water within the heater reaches 210°F, or if the water pressure in the heater
reaches 150 pounds. R ecreational vehicle water system s are closed system s and
during the water he ating cycle the pressure build-up in the water system will reach
150 pounds. W hen this pressure is reached, the pressure relief valve will open
and water will drip from the valve. T his dripping w ill continue until the pressure is
reduced to below 150 pounds, and the valve closes. This condition is norm al and
does not indicate a defective relief valve.
W AR N IN G ! D o not place a valve betw een the relief valve and the tank. D o
not plug the relief valve under any circum stances.
WATER WEEPING OR DRIPPING FROM PRESSURE
RELIEF VALVE
You m ay experience water weeping or dripping from your water heater's P ressure
and Tem perature (P & T ) R elief V alve when your water heater is operating. W ater
weeping or dripping from the P & T Valve does not always m ean the P & T V alve
is defective. As water is heated, it expands. The water system in a recreational
vehicle is a closed system and does not allow for the expansion of heated water.
W hen the pressure of the water system exceeds the relieving point of the P & T
V alve, the valve will relieve the excess pressure.
S uburban recom m ends that a check valve not be installed directly at the inlet to
the water heater tank. This will increase weeping of the pressure relief valve.
W AR N IN G ! D o not rem ove or plug the relief valve.
O ne way to reduce the frequency of this occurrence is to m aintain an air pocket
at the top of the water heater tank. This air pocket will form in the tank by design.
H owever, it will be reduced over tim e by the everyday use of your water heater.
T o replenish this air pocket:
1. T urn off water heater.
2. T urn off cold water supply line.
3. O pen a faucet in the R V .
4. P ull out on the handle of the P ressure R elief (P & T ) Valve and allow water
to flow from the valve until it stops.
5. R elease handle on P & T V alve - it should snap closed.
6. C lose faucet and turn on cold water supply; as the tank fills, the air pocket
will develop.
R epeat this procedure as often as needed to reduce the frequency of the weeping
of the P & T Valve. If the weeping persists after following this procedure, you m ay
elect to install an expansion or accum ulator tank in the cold water line between the
tank and check valve to reliev e the pressure caused by therm al expansion.
C ontact your local dealer for assistance.
THERMOSTAT AND MANUAL RESET
M O D E LS : S W 12D , S W 12D E , and S W 12D E M
S W 16D , S W 16D E , and S W 16D E M
T he m odel water heaters listed above are equipped with a high tem perature lim it
as a cut-off device. Tem perature above 180°F will cause m anual reset button to
trip shutting down m ain burner.
T o activate burner, the water tem perature m ust be below 110°F, push reset button
to re-activate burner.
Figure 12
THERMOSTAT AND MANUAL RESET
M O D E LS S W 12D E and S W 12D E M
S W 16D E and S W 16D E M
T he m odel w ater heaters listed above are equipped w ith a high tem perature lim it
as a cut-off device. Tem perature above 180°F w ill cause m anual reset button to
trip shutting down the electric elem ent.
T o activate elem ent, the water tem perature m ust be below 110°F, push reset
button to re-activate the electric elem ent.
DRAINING AND STORAGE INSTRUCTIONS
If R V is to be stored during w in te r m o n ths, the water heater m ust be drained to
prevent dam age from freezing.
1. T urn off electrical power to water heater either at the switch from the electrical
elem ent or a break er.
2. S hut off gas supply to water heater.
3. T urn off pressure pum p on water system .
4. O pen both hot and cold water faucets.
5. R em ove anode rod from tank .
6. Follow R V m anufacturer's instructions for draining entire water system .
N O T E : Be certain to refill water heater with water and rem ove all air from tank and
lines before re-lighting or before turning on electrical power.
ODOR FROM HOT WATER SYSTEM
O dor from the hot water system is not a service problem and m any water supplies
contain sufficient am ounts of su lp h u r to produce an odor. T he odor is sim ilar to
rotten eggs and is o ften referred to as "sulphur water". It is not harm ful - only
unpleasan t to sm ell. Sulphur water can be caused by a chem ical action or by
bacteria. The solution to elim inate is chlorination of the water system . Add about
six (6) ounces of chlorinated com m on household liquid bleach to each 10 gallons
in the water tank. Then run the chlorinated water throughout the system , opening
each faucet one at a tim e until you sm ell the chlorine. Let the R V sit for a few days
and the chlorine should take care of the problem . T hen you w ill need to take care
of the chlorine. R em ove the chlorine by flushing the system with fresh water. T his
m ay take several attem pts. You m ay consider adding a filtering system that
rem ove s c h lorine and prevents sulphur water. If the sulphur or rotten egg sm ell
continues, flush the system once again as described above and replace anode rod
as necessary.
REMOVING WATER HEATER
1. S hut off gas supply and disconnect gas supply line from water heater.
2. O n all Electric M odels, disconnect 120 V.A .C . supply at junction box m ounted
on heater.
3. O n all D S I Models, disconnect 12 V.D .C . power supply at junction b ox on
heater.
4. O n M odels S W 12D, S W 16D, S W 12DE and SW 16DE disconnect all wires at
m odule board.
5. S hut off water sup ply. D rain water from tank following instructions under
"D raining and S torage".
6. D isconnect hot and cold water lines from water heater.
7. R em ove screws or nails securing control housing to fram ed opening.
8. S lide heater out. T o reinstall, follow instructions in m anual under "Installation
Instructions".
WINTERIZING
If your water heater plum bing system is equipped w ith a bypass kit, use it to close
off the water heater, drain the water heater com pletely and leave the water heater
closed off (out of the system ) in the bypass position particularly if you are
introducing antifreeze into the plum bing system . A ntifreeze can be very corrosive
to the anode rod creating prem ature failure and heavy sedim ent in the tank. If the
plum bing system is not equipped with a bypass kit, and you intend to winterize by
adding antifreeze to the system , rem ove the anode rod (storing it for the winter)
and replace it with a 3/4" drain plug.
6
Figure 13