F.A.Q

During start-up and shut-down of a thermal oil heater there is always formation of condensate if the temperature falls below the exhaust gas dew point. The dew point temperature depends on the fuel. The dew point of crude oil is of approx. 50 – 60 °C. The dew point of other fuels however can be higher than the boiling temperature of pure water.

If the temperature is below this range, there will be always formation of condensate. Dependent from the conditions (air humidity, heating surface, plant content, etc.) formation of a considerable quantity of condensate is possible (several litres).

The condensate vaporizes because during normal operation, the plant is operating far above the dew point. This does not influence the operation of the heater. If the plant is started up once a week and is operated for several days the formation of condensate cannot be detected from the outside, because the condensate evaporates before it escapes at the gasket of the heater cover. If, however, the plant is started-up and shut-down very frequently, the condensate will escape at the heater cover because new condensate is formed before the gasket is dry. This is no critical situation because the gasket of the heater cover is of ceramic material. Humidity does not influence the quality of the gasket.

A further possibility for the escape of humidity can be rain coming through the chimney or the exhaust gas duct. Normally, chimneys are constructed in such a way that rain cannot enter the heater. Under certain conditions, if e.g. the condensate drain of the chimney is closed and is not emptied regularly, rain can get into the heater and escape through the ceramic gasket of the burner plate.

Trouble shooting

Symptom	Probable cause	Action
Continual drop of differential pressure	Filters are dirty	Shut-down the plant and clean all filters. Analyse dirt particles and if there are coke deposits contact maxxtec immediately
Flow control FIZA - Pos. 6.12.1 shuts down the firing, warning light shines	Decline in pump output	Check coupling, motor and bearings and if necessary replace them. (follow the manufacturer’s instructions). Check if there are changes in the system
Pressure fluctuations	Leak in the system	Repair the leaks
	Shut-off valves Pos. 5.1.1 are closed or by-bass valve settings are changed	Open the shut-off valves and reset the system
	Gas or air in the system	Vent the system, check for noises in the piping
	Water in the system	Degas the system
	Carrier oil no longer good (e.g. flash point has dropped)	Analyse the thermal oil and inform maxxtec
	Overheated carrier oil because of irregular heating	Check flame geometry and settings. Reset the firing. Call customer service. Analyse the thermal oil

Level control

Symptom	Probable cause	Action
Firing shuts down, warning light shines	Oil level is expansion tank Pos. 7.2.1 too low	Refill carrier oil. Search for the cause of the loss
	Float switch defective	Check the instrument and if necessary replace it

Safety temperature limiter TZA+ Pos. 6.4.1 feed line

Symptom	Probable cause	Action
Firing shuts down, warning light shines	Wrong setting of the safety temperature limiter TZA+ Pos. 6.4.1.	Reset correctly
	Wrong setting of the heater controller Pos. 6.2.1.	Check settings and reset correctly
	Temperature gauge TI Pos. 6.15.1 defective	Check temperature and inspect the temperature sensor

Safety temperature limiter TZA+ Pos. 6.5.1 exhaust gas

Symptom	Probable cause	Action
Firing shuts down, warning light shines	Wrong setting of the temperature limiter TZA+ Pos. 6.5.1.	Check and reset correctly
	Heating surface of the heater Pos. 1.1.1 is dirty	Clean it as described in § 6.2.
	Firing capacity set too high	Check the fuel consumption and reset the firing. Contact the customer service. Contact maxxtec about possible further actions (e.g. checking heating surface for coke deposits or thermal overload)
	Exhaust gas bypass in heater Pos. 1.1.1.	Request a service engineer from maxxtec to inspect the inside of the heater and the gaskets between the flue gas ducts