I. Explanation of special terms for heating units
1 Primary side: refers to the heat source, such as hot water or steam in the boiler room.
2 Secondary side: refers to heat users, such as floor heating, radiators, central air conditioning and other heat users.
3 Water supply: whether primary or secondary side, hot water for the water supply, i.e., high temperature piping for the water supply.
4 Return water: whether primary or secondary side, cold water for the return water, that is, the low temperature pipeline for the return water.
5 High-temperature water: temperature higher than or equal to 100 degrees of water, the national norms for 130/80 degrees, that is, the water supply temperature of 130 degrees, the return temperature of 80 degrees.
6 low-temperature water: the temperature is lower than 100 degrees of water, the national norms for 95/70 degrees, that is, the water supply temperature of 95 degrees, the return temperature of 70 degrees. Note: High temperature water, low temperature water are defined for the primary side of the system.
Second, the normal operation of the unit parameter display law
1 The water supply temperature is higher than the return water temperature, and the water supply pressure is higher than the return water pressure.
2 The difference between the primary side water supply pressure and the return water pressure should be greater than or equal to 0.05MPa.
3 The difference between the inlet and outlet pressure of the secondary side of the plate heat exchanger should be less than or equal to 0.15MPa.
4 If the primary side of high-temperature water, the temperature difference between the water supply temperature and the return water temperature should not be higher than 40 degrees.
5 If the primary side of the low-temperature water, the temperature difference between the water supply temperature and the return water temperature should not be higher than 25 degrees.
6 If the secondary side is heated by radiators, the temperature difference between the water supply temperature and the return water temperature must not be higher than 25 degrees.
7 If the secondary side is heated by underfloor heating or air-conditioning, the temperature difference between the supply water temperature and the return water temperature must not be higher than 14 degrees.
Common faults and troubleshooting methods
1 unit fault indicator light, that is, the yellow indicator light on the control cabinet, what to do?
The fault indicator light indicates that the corresponding water pump is overloaded, the motor current exceeds the rated current, and the thermal relay plays a protective role. It can be disarmed by pressing the reset button on the thermal relay to reset it. Note that the thermal relay must be cooled down before it can be reset, otherwise the reset will not be effective.
2 There is pressure in the system, but the pressure gauge shows 0, how is it?
If the needle valve of the pressure gauge is closed, the pressure gauge will always show 0. During the operation of the unit, make sure that all needle valves of the pressure gauge are fully open.
3 What happened to the overpressure on the secondary side? What should I do if overpressure occurs? How to prevent overpressure in the secondary system?
When the system is first run, the secondary temperature is relatively low, after the make-up water reaches the fixed pressure value, as the temperature continues to rise, the pressure of the secondary system will rise, at this time, one is to exhaust more, and the second is to drain the water. When the water drain to open the secondary return line drain valve can be. When the system temperature is stable, the pressure will not rise again.
4 How to judge whether the filter is clogged?
If the temperature difference between the primary water supply temperature and the primary return water temperature is very large, high temperature water more than 45 degrees above, low temperature water more than 30 degrees above, and the secondary water supply is not hot, this time, please check the primary water supply at the filter is clogged. If the temperature difference between the secondary water supply temperature and the secondary water return temperature is very large, the temperature difference between the floor heating is more than 15 degrees, the temperature difference between the radiator heating is more than 30 degrees, and the pressure difference is very small, please check whether the filter at the secondary water return is clogged.
5 How to judge whether the heat exchanger is clogged?
If the pressure difference between the primary supply and return water or the inlet and outlet pressure difference of the secondary heat exchanger exceeds 0.15MPa or more, and the secondary water supply temperature is not hot, check whether the heat exchanger is clogged. The method of checking is to dismantle and clean the heat exchanger.
6 What are the reasons for the system not heating? How should it be analysed?
If the secondary water supply temperature is low and not hot, analyse the following reasons:
(1) Insufficient water supply flow on the primary side.
Check whether all the valves of the primary water supply and return pipelines are open.
Check whether the primary water supply filter is clogged.
Check whether the temperature control valve is normal.
If all the valves are open, then judge the pressure difference between the primary supply and return water, if the pressure difference is less than 0.05MPa, ask the heat company to increase the flow.
If the pressure difference between primary supply and return water is more than 0.15MPa, please clean the heat exchanger.
(2) secondary side of the system is not smooth check the secondary side of the water supply and return pipeline all the valves are open.
The secondary side filter is clogged.
Initial operation of the equipment, check whether the system piping is clogged.
Secondary side heat exchanger inlet and outlet pressure difference is higher than 0.15MPa, heat exchanger clogging, please clean the heat exchanger.
(3) If it is the first time to run the equipment, check whether the water inlet and return pipelines are reversed.
7 What is the problem that the system make-up water can not be filled in?
The make-up water pump keeps turning, but the pressure does not rise. If the make-up water pump keeps running and the pressure never reaches the set value, exhaust the pump and the system. Most of the time, poor make-up water is caused by the system collecting air.
The make-up water pump reverses, the impeller or coupling falls off, etc. Check the pump inlet and outlet water system (e.g. whether the valve is open or the pipe is blocked), etc.
8 inverter water supply or circulation pump is not automatic, inverter is not controlled, etc. What is the reason?
Check whether the changeover switch is in the position of frequency conversion or automatic position, the frequency converter must be in the position of frequency conversion or automatic position in order to work normally. Check whether the signal feedback is connected wrongly. Check whether the parameter setting of the frequency converter is correct. Check whether there is an alarm code in the operation disc of the frequency converter, the number beginning with F is the fault code, the number beginning with R is the warning code, the warning code does not affect the operation of the frequency converter, while the fault code appears, you must reset the frequency converter, the frequency converter must be reset, the frequency converter must be reset.
The warning code does not affect the operation of the inverter, and after the fault code appears, the inverter must be reset for the inverter to continue to work. If the fault code appears, please press the EXIT key at the upper left corner of the inverter operation screen. Check the industrial frequency or other circuits (e.g., whether the contactor is activated or not, whether the trigger relay is activated or not), etc.
9 What should I do if the secondary water supply temperature is too high?
If the user feels that the water supply temperature is too high and the room is too hot, the best way is to close the primary water supply valve. Please note that the primary water supply valve must be turned down and the return valve is fully open.
Check whether the primary side of the temperature control valve is out of order in the full open state.
10 What is the problem of excessive water pump noise?
When the unit is running for one or two heating periods, due to mechanical wear and tear, the noise will become louder. Check whether the fan cover is loose, whether the bearings are out of oil or damaged, whether the impeller is rubbing against the pump body, whether the motor is concentric with the pump, and exhaust the pump.
The pump must be maintained regularly, adding lubricant, replacing wearing parts and so on.
11 What happens when the charge pump is frequently replenished and the pressure drops rapidly after it stops?
If the unit has been operating normally for a long period of time, and there is frequent replenishment of water, please do the following checks:
Check the secondary system for leakage of pipes or valves, etc.
Check whether the check valve in front of the make-up pump is not tight, and the phenomenon of backflow. Check method is to stop the make-up water pump, close the inlet valve of the make-up water pump, and then open the exhaust valve at the outlet of the make-up water pump, if there is water discharged, it means that the check valve in front of the make-up water pump is not tight, and needs to be replaced.
12 What happens when I turn on one circulating pump and the other circulating pump is also spinning?
During the operation of the unit, if one circulating pump is switched on and the other circulating pump is also rotating, and in reverse, it means that the check valve in front of the pump that is not switched on is not tight, and needs to be replaced. If you can't replace the check valve temporarily, please close the butterfly valve before and after the pump to prevent water backflow.
13 How can I tell if the pump is turned correctly if the unit is equipped with a shielded pump?
The most reliable way to judge whether the shielded pump is turning correctly is to measure the current with a clamp-type ammeter, and the current for forward rotation is greater than the current for reverse rotation. If the pump is an ordinary pump, observe the direction of rotation of the motor blades or coupling.
14 pump start run indicator light, and the pump does not run, how is it?
Check the circuit breaker in the control cabinet, and put all the circuit breaker contacts in the absorbing state. (Whether the main circuit of the motor is in the state of lack of phase or broken circuit)
