Armstrong DRV40 - Temperature Control Issues

Intelligent System Solutions® STEAM ● AIR ● HOT WATER
armstronginternational.com
Armstrong Hot Water, Inc. – DRV40-80 Gen. 2 Troubleshoot Guide
221 Armstron
g
Blvd.
,
Three Rivers
,
Michi
g
an 49093
–
U.S.A. Phone:
(
269
)
27
9
-
3602 Fax:
(
269
)
27
9
-
3130
Yes
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Temperature Control Issues
Has the valve been reset
(
i.e.
p
owered off
,
then on
)
?
Check
Yes
No
Reset the valve by
powering down & then
p
owerin
g
back on
Has the valve been re-
calibrated?
No
Calibrate valve
No
Isolate recirculation;
create sufficient demand
(10gpm min.) & check
performance
Does the valve control
under minimum demand?
Does the system have
sufficient recirculation flow
(10gpm min.)?
Yes
Yes
Yes
Are supply pressures
nominally equal (within
5psi)?
No
Check recirculation
pump rating; ensure is
capable and running at
min. of 10gpm; if not,
increase pump size
No
E
q
ualize
p
ressures
Yes
Does the system have
sufficient recirculation loop
temperature loss (2deg
min
)
?
No
Reduce size of
recirculation pump or
slow down flow
Yes
Is there adequate supply
water temperatures (hot &
cold su
pp
l
y)
No
Ensure hot water
supply is > than valve
setpoint (min. 2deg F) &
cold water supply is <
than valve setpoint
(min. 2deg F)
Are the valve internals free
of debris and clean?
No
Remove valve internals
and thoroughly clean
Yes
Does the recirculation
pump run continuously
without an Aquastat?
No
Remove aquastat;
recirculation pump
should run continuousl
y
Yes
Are the O-Rings/Seals in
good condition & not
preventing the spool
travel?
Yes
No
Remove valve internals
& check O-rings/Seals
to ensure they are
smooth; if not, replace
Is the spool lock nut on the
drive shaft tight preventing
any spool slop?
Tighten lock nut to 80-90
in-lb
No