Keston Thermomatic RSM20/FB, Installation & Servicing Instructions Manual, Page: 31 / 46

Page 31
Fig. 7.12. CONDITION 12.
Does water escape from the safety
valve as pressure exceeds 3 bars?
Does water escape from the
safety valve below 3 bar?
(pressure relief valve)
Does w ater escape during the
heating cycle?
Dirty or faulty valve. Let
w ater pass through the
valve, turning the red knob,
so to clean it. If necessary,
replace safety valve.
Too high boiler
pressure?
Filling cock dirty , faulty
or does not stand the
pressure?
Is the filling flexible pipe
leaking?
Water Leakage from the
boiler?
Does w ater escape from the
air vent valve?
Faulty air vent valve, replace it.
Yes
Is the w ater gauge leaking?
Is some w asher in the hydraulic
system leaking?
Faulty flexible pipe, replace it.
Faulty water gauge, replace it.
Untight or faulty w asher.
Tighten or replace it.
No
Clean up or replace the
filling cock.
Decrease the boiler
pressure to 1 bar.
Is the expansion vessel
discharged?
Fill up the vessel to 1 bar
of pressure.
Does the vessel hold the
pressure?
Leaking valve or faulty
membrane. Replace the
vessel.
Yes Yes
Yes Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No