Designs, materials, weights and performance ratings
are approximate and subject to change without notice.
Visit
armstrong
international.com for up-to-date information.
Armstrong
International
221 Armstrong Blvd., Three Rivers, Michigan, 49093 - USA
Tel. (269) 279-3602 Fax. (269) 279-3130
Page 32 of 44
DRV40-80 Gen. 2 Troubleshoot Guide
Temperature Control Issues
Has the valve been reset
(i.e. powered off, then on)?
Has the valve been
recalibrated?
Does the valve control
under minimum demand?
Does the system have
sufficient recirculation flow
(10gpm min.)?
Are supply pressures
nominally equal
(within 5psi)?
Reset the valve by
powering down & then
powering back on
Calibrate valve
Isolate recirculation;
create sufficient demand
(10gpm min.) & check
performance
Check recirculation
pump rating; ensure is
capable and running at
min. of 10gpm; if not,
increase pump size
Equalize pressures
Check
Yes
Yes
No
No
No
No
No
Yes
Yes
Yes
Does the recirculation
pump run continuously
without an Aquastat?
Is there adequate supply
water temperatures
(hot & cold supply)
Are the valve internals
free of debris and clean?
Are the O-Rings/Seals
in good condition & not
preventing the spool
travel?
Remove aquastat;
recirculation
pump should run
continuously
Reduce size of
recirculation pump or
slow down flow
Ensure hot water
supply is > than valve
setpoint (min. 2°F) &
cold water supply is <
than valve setpoint
(min. 2°F)
Remove valve
internals and
thoroughly clean
Remove valve
internals & check
O-rings/Seals to
ensure they are
smooth; if not,
replace
Tighten lock nut to
80-90 No in-lb
Yes
Yes
No
Yes
No
No
No
No
No
Yes
Yes
Does the system have
sufficient recirculation loop
temperature loss
(2°F min)?
Is the spool lock nut
on the drive shaft tight
preventing any spool
slop?
Summary of Contents for Digital-Flo DF41540
Page 45: ...Notes...
