Relief$Valve
A$new$pressure$relief$valve,$complying$$
with$the$Standard$for$Relief$Valves$and$
Automatic$Gas$Shut`Off$Devices$for$Hot$
Water$ Suppl y$Sys tems, $ANSI$ Z21. 22/$
CSA$4.4,$must$be$installed$at$the$hot$water$
outlet$connection$of$the$water$heater$at$
the$time$of$installation.$Local$codes$shall$
govern$the$installation$of$relief$valves.
For'safe'operation'of'the'water'heater,'be''
sure'that:
●$$The'pressure'rating'of'the'relief'valve'
must'not'exceed'150'psi'(1034'kPa),'the'
maximum'working'pressure'of'the'water'
heater'as'marked'on'the'rating'plate.
●$$The'BTUH'rating'of'the'relief'valve'must'
equal'or'exceed'the'BTUH'input'of'the'
water'heater'as'marked'on'its'rating'plate.
●$$No'valve'of'any'type'should'be'installed'
between'the'relief'valve'and'the'water'
heater
●$$Discharge'from'the'relief'valve'should'
be'piped'to'a'suitable'drain'to'eliminate'
potential'water'damage.'Piping'used'should'
be'of'a'type'approved'for'the'distribution'of'
hot'water.
●$$Hot'and'cold'water'lines'should'be'
insulated'up'to'the'water'heater.'Refer''
to'page'23'for'details.
●$$The'discharge'line'must'be'
NO'SMALLER'than'the'outlet'of'the'
relief'valve'and'must'pitch'downward'to'
allow'complete'drainage'(by'gravity)'of'
the'relief'valve'and'discharge'line.
●$$The'end'of'the'discharge'line'should'not'
be'threaded'or'concealed'and'should'be'
protected'from'freezing.'No'valve'of'any'
type,'restriction'or'reducer'coupling'should'
be'installed'in'the'discharge'line.
Notice:'Local'codes'govern'the'installation'
of'relief'valves.'If'local'codes'require'that'a'
temperature'and'pressure'relief'valve'should'
be'installed,'the'manufacturer'recommends'
a'type'40XL'Watts'T&P'relief'valve'or'an'
equivalent'model'be'used.
Notice:'Manual'operation'of'relief'valves'
should'be'performed'at'least'once'a'year.'Turn'
off'the'electrical'power'and'gas'shutoff'valve.'
Lift'and'release'lever'on'the'relief'valve'and'
check'the'manual'operation'of'the'relief'valve.'
You'should'take'precaution'to'avoid'contact'
with'the'hot'water'coming'out'of'the'relief'
valve'and'to'prevent'water'damage.
Notice:'If'the'relief'valve'on'the'system'
discharges'periodically,'a'problem'exists'and'
service'to'the'water'system'is'required.
The'vinyl'tubing'as'shown'is'supplied'and'
connects'to'the'drain'valve'located'at'the'hot'
water'outlet'as'shown'in'the'diagram'at'left.'
Route'the'other'end'of'the'vinyl'tubing'to'the'
drain'pan'or'a'suitable'drain'where'leakage'
from'the'heater'will'not'result'in'damage'to'
the'area'adjacent'to'the'heater'or'to'lower'
floors'of'the'structure.
Relief
Valve
Pressure
Relief
Valve
Discharge
Water
Shutoff
Drain
Valve
Valve
Hot Water
Supply
Union
Outlet
Drain
Tube to
suitable
drain
Cold
Water
Supply
Inlet
Line
Notice:'The'above'illustrates'
a'pressureEonly'relief'valve.'If'
local'codes'require'a'combination'
temperature'and'pressure'relief'
valve'be'installed,'an'extension'
piece'may'be'needed'to'ensure'that'
the'valve'probe'is'not'directly'in'
the'flow'path'of'the'water.'
17
Drain'Valve'
shown'on''
right'without'
tubing.
AP15317 (10_09) DV Gas Manual 10 30 09.indd 17 11/9/2009 3:10:28 PM