Leslie Controls NYC Heat Exchanger Supplement - Manual (Page 6)

Page 6 of 9
5. Output temperature gauge reads 120 degrees F.
6. Temperature switches are set for 180 degrees F
for the first switch and 130 degrees F for the
second switch.
7. If step 1 or two is not correct then correct
condition and wait for 10 minutes while the unit
sets to normal conditions.
8. If any or all of steps 3, 4 5 or 6 are not correct
then continue with this troubleshooting guide.
B. OPERATION DUE TO OVER
TEMPERATURE CONDITIONS
1. Check that temperature switches are properly set.
First switch = 180 degrees F
Second switch = 130 degrees F
2. If unit is in over temperature condition, then turn
off steam supply to side not working properly and
wait 10 minutes for unit to cool down. Reset light
is out, No pump flow light is out and both No. 1
and No. 2 heater over temperature lights are out
and either Pump 1 or Pump 2 light is on.
3. Once the unit has cooled down turn the steam
supply back on.
4. Insure that there is some flow in building by
turning on a hot water tap.
5. Temperature of the outlet water should slowly
increase. Water temperature will, for a short
time, run over 120 degrees F. It will come down
after 5 minutes.
6. If water temperature does not increase then go to
Section C. If water temperature continues to
increase then go to Section D.
C. WATER TEMPERTURE NOT
GETTING WARM
1. Check that pipes before solenoid valves are hot.
2. If pipes or pipe is not hot, then check cold water
supply valve to heat exchangers is turned on. If
not then turn it on. Read note below.
3. Check condensate drains and steam traps are clear
and not backing up to heat exchanger.
4. Check that pipes after the solenoid valves are hot.
5. If not hot, then isolate the side and remove,
inspect and replace the solenoid seat if it is
damaged.
6. If hot then check gain valves to insure they are
not fully open.
7. If gain valve settings are correct then remove and
replace final blend valve element.
D. OVER TEMPERATURE WATER
1. Check that gain valves are set properly. See “Gain
Valve Procedure” following this section.
2. Check temperature switch settings.
3. Isolate system to side that is over temperature.
4. If temperature is changing quickly then shut down
and replace solenoid seat for this side.
5. If primary temperature switch is tripping then
change element of primary blend valve. If
secondary switch is tripping then check and or
change secondary element.
GAIN VALVE PROCEEDURE
IMPORTANT!
1. Slowly supply water pressure to primary blend
valves after full water pressure is reached then
open up cold water supply to secondary blend
valves slowly. Not doing so will cause solenoid
valve seat to come unseated. An unseated
solenoid can cause temperature to fluctuate up
and down or cause a no hot water condition.
CAUTION!
Never set temperature switches higher than
recommended setting. Doing so will damage the
solenoid valves and the mixing valves.
IMPORTANT!
TO TROUBLESHOOT THE SYSTEM SHUT
ONE SIDE OF THE SYSTEM DOWN, FOLLOW
THE CHECKS BELOW AND REPEAT ON THE
OPPOSITE SIDE OF THE SYSTEM.
NOTE
Gain adjuster valves, are used to adjust cold water to
final blend valve to insure holding set temperature
over flow range of unit. Valves are generally set at
4.5 turns from full open position, however they
should be adjusted for each installation since each
building has its own characteristics.
Valves should be re-adjusted when season
changes from winter to summer.