Bradford White U2TW75T*RN, Руководство по обслуживанию

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U TT W SERVI C E PRO C EDURE V I
Blower Temperature Switch Testing
and R eplacement
Blower Temperature S witch
Testing.
W AR N I N G
11 5 volt potential e x posure. Use caution
to avoi d personal injur y .
18
Disconnect wire leads to
switch. Usin g a multi-meter
set to the ohms settin g , is
there continuity between the
switch terminals ?
Switch O K
Cool switch to
below 1 3 0°F
N
Y
Switc h Settin g
O pens on rise @ appro x imatel y 1 6 5°F
A uto resets on f all @ appro x imatel y 130°F
S t e p 1. Po s i t ion g a s con tr ol pow e r s wi t ch
to the “OFF” position .
S t e p 2 . R e mov e t h e t h r ee s c r e w s (Phillip s
s c r e w d r iv e r ) f r om con tr ol a cc e ss
cov e r on blow e r a nd r e mov e cov e r
( s ee pho t o s 17 a nd 18).
S t e p 3. Loc a t e blow e r t e mp e r a t u r e s wi t ch
( s ee pho t o 19).
Reconnect wire leads and
observe heater operation. Do
exhaust g as temperatures rise
to or above 16 5 °F ?
Replace switch
(see pa g e 25 ).
Y
N
Do switch contacts
open ?
Do switch contacts
open ?
N
Y
Replace switch
(see pa g e 25 ).
N
Y
Exhaust
temperature is too
hot.
C ommon causes f or
high e x haust temperature
1 . V ent length is b elow minimum allowa b le.
2 . V ent diameter not to speci f ication.
3 . R estricted dilution air inlet.
4 . M issing or deteriorated f lue b a ff le.
5 . G as pressure is out o f speci f ication.
Blower temperature
switch location
19
Air mixin g inlet
P a g e 24
Gas Control shown in the “OFF” position
Control Access
Cover Screws
17
R
24