Problem
Cause
Solution
A. Assembly discharges
from differential relief
valve during no flow
condition.
Fouled first check
Disassemble and clean No. 1
check valve
Fluctuating inlet pressure
Control supply line water
pressure.
Install a soft seated, spring
loaded, check valve up-
stream of the assembly.
Outlet pressure higher than
inlet pressure & leak in No. 2
check valve
Disassemble, clean #2 check
valve & identify cause of
backpressure
Leak through diaphragm or
around flange bolt holes of
relief valve
Service relief valve
Pressure relief valve does not
close
See problem D
B. Assembly discharges
from differential relief
valve during a flow
condition.
No. 1 check valve wedged
open
Disassemble and clean No. 1
check valve
O-ring displaced from groove
in 1st check
Disassemble and replace
Pressure relief valve does not
close
See problem D
Fluctuating line pressure
C. Differential pressure
relief valve does not
open during test
Differential pressure across
No. 1 check valve stays above
2.0psi due to leaking outlet
gate valve
Repair shutoff valves
Weak or broken relief valve
spring
Disassemble and replace
relief valve spring
Shutoff seat tube bound in
body
Disassemble and repair
Plugged hydraulic hose
Disassemble and repair
D. Pressure relief valve
does not close
Debris on sealing surface
Remove relief valve and clean
Plugged hydraulic hose
Disassemble and clean
Damaged seat or rubber
shutoff disc
Remove relief valve assembly
and replace
Ruptured diaphragm
Disassemble and replace
diaphragm
Wrinkled or improperly in-
stalled diaphragm
Disassemble and properly
position diaphragm
Troubleshooting Guide
Air Gap Drain
11
3
⁄
4
7.00
2” Pipe
Thread
RP-IS-994/994RPDA 1319
EDP# 1915230
© 2013 Watts
USA:
Tel: (978) 688-1811 • Fax: (978) 794-1848 • www.watts.com
Canada:
Tel: (905) 332-4090 • Fax: (905) 332-7068 • www.watts.ca
limited warranty:
Watts Regulator Co. (the “Company”) warrants each product to be free from defects in material and workmanship under normal usage for a period of one year from the date of
original shipment. In the event of such defects within the warranty period, the Company will, at its option, replace or recondition the product without charge.
THE waRRanTy SET FORTH HEREin iS GiVEn EXpRESSly and iS THE Only waRRanTy GiVEn By THE cOMpany wiTH RESpEcT TO THE pROducT. THE cOMpany MaKES nO OTHER
waRRanTiES, EXpRESS OR iMpliEd. THE cOMpany HEREBy SpEciFically diSclaiMS all OTHER waRRanTiES, EXpRESS OR iMpliEd, includinG BuT nOT liMiTEd TO THE iMpliEd
waRRanTiES OF MERcHanTaBiliTy and FiTnESS FOR a paRTiculaR puRpOSE.
The remedy described in the first paragraph of this warranty shall constitute the sole and exclusive remedy for breach of warranty, and the Company shall not be responsible for any incidental, special
or consequential damages, including without limitation, lost profits or the cost of repairing or replacing other property which is damaged if this product does not work properly, other costs resulting
from labor charges, delays, vandalism, negligence, fouling caused by foreign material, damage from adverse water conditions, chemical, or any other circumstances over which the Company has no
control. This warranty shall be invalidated by any abuse, misuse, misapplication, improper installation or improper maintenance or alteration of the product.
Some States do not allow limitations on how long an implied warranty lasts, and some States do not allow the exclusion or limitation of incidental or consequential damages. Therefore the above
limitations may not apply to you. This Limited Warranty gives you specific legal rights, and you may have other rights that vary from State to State. You should consult applicable state laws to
determine your rights.
SO FaR aS iS cOnSiSTEnT wiTH applicaBlE STaTE law, any iMpliEd waRRanTiES THaT May nOT BE diSclaiMEd, includinG THE iMpliEd waRRanTiES OF
MERcHanTaBiliTy and FiTnESS FOR a paRTiculaR puRpOSE, aRE liMiTEd in duRaTiOn TO OnE yEaR FROM THE daTE OF ORiGinal SHipMEnT.
A Watts Water Technologies Company
waRninG:
This product contains chemicals known to the
State of California to cause cancer and birth defects or
other reproductive harm.
For more information: www.watts.com/prop65
For repair kits and parts, refer to our
Backflow Prevention Products Repair
Kits & Service Parts price list PL-RP-BPD
found on
www.watts.com.
