14
SYMPTOM
POSSIBLE
ACTION
CAUSES
No flow
Low Pressure
Intermittent discharge
from P&T or P valve(s)
Continuous
discharge from
P&T or P valve(s)
Mains service valve not open
Blocked filter.
Service valve not fully open or
partially blocked filter.
Restricted delivery pipework
Low mains pressure.
Expansion vessel pressure below
3.0 bar or faulty.
Wrongly set or faulty Inlet Pressure
Reducing Valve.
Defective expansion relief valve or
debris or scale on seating of valve.
Defective or incorrectly set cylinder
thermostat (ie temperature set too
high) allowing water to overheat.
Crossflow from uncontrolled cold
water mains supply to mixer tap or
shower valves.
Faulty expansion vessel.
Open stop valve or replace.
Clean filter in base of Pressure
Reducing Valve.
Ensure service valve is fully open or
clean filter in PRV.
Replace damaged or
old pipework.
Check incoming mains pressure or
discuss with local water supplier
Replenish or replace in accordance
with instructions in the maintenance
section.
Replace PRV
Operate expansion relief valve
mechanism to clear debris.
If discharge does not stop replace
expansion relief valve.
Check setting and operation of
cylinder thermostat (55-65
o
C).
Replace if necessary.
Check mixer taps and shower valve
and fit check valves or area
pressure controls if required.
Alternatively supply cold water to
mixer tap or shower valves from
balanced supply position on inlet
control set.
Recharge or replace.
Water fails to heat
Not enough
hot water
Water not
hot enough
Water fails to heat
Boiler not working. Pump and/or
control valve not operating.
Cylinder thermostat upper limit stat
has operated.
Cylinder too small.
Boiler not providing enough heat.
Cylinder thermostat settings
incorrect.
Upper limit cut-out switch has
operated in immersion heater.
Check boiler controls.
Check control functions and
replace faulty parts.
Reset the button on the dual
cylinder thermostat after
investigating cause of overheating.
Check storage specification is
adequate. Telford Service
Department can help.
Adjust thermostat to between 55
o
C
and 65
o
C. Ensure boiler
thermostat is set to above 75
o
C.
Turn off electricity supply, open
cap of I/H and reset cut-out
(red button) or press external reset
button if fitted.
PROBLEM
Solving:
INDIRECT
DIRECT
NEW TORNADO/TEMPEST 25336 19/4/05 12:25 PM Page 5
