MegaTherm Commercial Pool Heating BoilerPage 17
SECTION 6. PARTS
1. Symptom: heater is pounding, knocking or emitting steam from relief valve
Possible Cause |
| What to Do |
A. Low or no water flow | A. | Is the heater wired into the filter pump circuit so that the heater cannot fire |
(most likely). |
| unless the pump is running? |
|
| Check to see that all valves in system are open to be sure that water can |
|
| circulate through the heater. |
|
| Check pool filter, clean if clogged. |
|
| Examine heater pump for clogged or frozen impeller. |
|
| Check flow switch for proper operation and range setting. |
B. Debris from system piping | B. Remove header covers. Examine all tubes and waterways. Clean out tubes. | |
is blocking tubes. |
| Use new gaskets when reassembling. |
C. Scale has formed in tubes | C. | Clean tubes with tube cleaning kit. Determine hardness. Check water flow, and |
from high mineral content. |
| clean pool filter. |
2. Symptom: heater will not fire
A.Heater not getting power.
B.Operating or safety control has opened circuit to electric gas valve.
C.Pilot flame is out.
D.Manual reset device has tripped.
E.No gas pressure to burners.
F.Electric gas valve operator is burned out or shorted.
G.Pump does not run.
H.Pump runs, but flow switch not closing.
I.Field interlock open.
A.Check to see that power switch is "ON." Use testing device to trace power to heater power source. Check fuse and secondary voltage in heater control.
B.Turn off power. Check continuity across terminals of each operating and safety control switch up to the electric gas valve. Replace defective control.
C.Relight pilot per instruction.
D.Reset pilot safety and all manual reset safety switches. Follow instructions for
E.Trace gas line to service shutoff cock. If service cock is open, trace gas line to meter. If no pressure is present at meter, call for public utility service. If gas is present in heater inlet, check pressures in following sequence: (1) downstream from pressure regulator; (2) downstream from electric gas valve. Replace or adjust as necessary.
F.Disconnect wiring harness at gas valve terminals. Check continuity of actuator coil. If open circuit or short is indicated, replace coil or operator.
G.Operate in manual. Check power to pump from relay, Check that pump/motor is free to rotate. Replace relay or motor as necessary.
H.Check continuity across flow switch. Inspect paddle for proper movement. Adjust flow range setting.
I.Jumper terminals and isolate problem in other equipment.
3. Symptom: pressure relief valve leaking intermittently or steadily
A. Faulty relief valve. | A. Replace with a new relief valve with proper setting (see rating plate). |
4. Symptom: soot in flueways or in tubes, or noxious fumes from bad combustion
A.Combustion air supply to heater room is inadequate.
B.Stack or vent is blocked or restrictive.
C.Severe downdraft is causing spillage of flue products into room.
A.Check air supply opening. Look for debris in screen or louvre which covers combustion air opening, or for objects blocking the opening.
B.Look for blocked stack and excessive number of elbows in stack or excessive length of horizontal runs.
C.Check for (1) proper vent cap on stack; (2) adequate height of stack above roof; (3) equipment exhausting air from inside of building; and (4) proper installation of draft diverter.
D.Gas pressure to burners is excessive. D. Check gas pressure with manometer, and adjust with heater firing at full rate.
E.Heater not fitted for the fuel supplied. E. See nameplate for correct fuel.
F. Heater installed at high altitude | F. Installations at altitudes in excess of 2000 ft. above sea level are subject to |
without proper derating. | jurisdiction of the local inspection authorities. Check orifice size, contact your |
| dealer or factory for proper size. |
5. Symptom: water dripping in firebox
A.Tube in heat exchanger has overheated and ruptured.
B.Heater is condensing from low inlet temperature.
A.Tube failure is almost always caused by scale formation in the tube, or inadequate water flow through the heater.
B.Check bypass valve adjustment.
