Under normal circumstances, the hot water boiler only needs regular water replenishment. If the boiler frequently needs a large amount of water replenishment, it means that there is a problem inside the boiler, which needs to be discovered and solved in time. Zhengzhou Fangkuai Boiler Factory has summarized the following possible reasons when the boiler always needs to make up water for your reference.
Phenomenon: The display value of the pressure gauge drops frequently.
The water pressure of a normal boiler must be greater than 0.8bar, and the water supplement period should be more than 3-6 months. The boiler is connected with the heat dissipation system in the room to form a heating system. The water pressure gauge on the boiler shows the pressure value of the entire heating system, so make-up water is to make up the entire heating system. Therefore, in most cases, the frequent replenishment of water is a possible problem in the heating system, not a boiler problem.
Reason 1: the newly commissioned heating system
The newly commissioned heating system had a lot of air in the early stage, and the automatic exhaust valve of the system caused the pressure to drop, which required multiple water replenishment.
Reason 2: There is a leak in the heating system
The joints of the exposed pipes or buried pipes of the heating system may be leaky and have little leakage. Since the boiler is in the heating state, the entire system is hot, so the leaked water evaporates quickly. It is difficult to spot the leaks with the naked eye.
If there is a boiler pressure drop and the leak cannot be found, it is recommended to check whether the boiler is leaking.
Inspection Method:
Stop running the hot water boiler, close the heating supply and return water valve under the boiler (make sure the valve can be closed), disconnect the boiler from the system directly, fill the boiler to an integer value, and observe for a period of time to see if there are fluctuations in the water pressure gauge. This method can simply determine whether it is a boiler problem or a water leakage problem in the heating system pipeline behind the valve.
Reason 3: Failure of the expansion water tank in the boiler
Failure of the expansion tank will cause the system pressure to exceed 3 bar when the hot water boiler is heating up, and the safety valve will be protected by water leakage. Please contact the after-sales team of the boiler manufacturer for replacement.
Reason 4: The water supply valve is not closed tightly
If the water supply valve is not closed tightly and the pressure of the tap water pipe network is low, the system will lose pressure when using domestic hot water.
Solution: If there is frequent water replenishment, you need to contact the after-sale boiler factory to check the heating system as soon as possible to avoid damage to the hot water boiler caused by long-term water replenishment.




We, Zhengzhou Fangkuai Boiler Co., Ltd. (Fangkuai), are excited to announce our participation in the Indonesia International Heating Technology Exhibition 2025. We will be showcasing our advanced boiler systems engineered for higher efficiency, lower emissions, and sustainable energy performance. Join us at Booth No. B1-08 from November 5–7, 2025 at the Jakarta Convention Center.
The event brings together EXPO BOILER, EXPO BIOMASS, EXPO PUMPS & VALVES, and EXPO CRANE — creating a comprehensive platform for technology exchange and business collaboration across the industrial heating and energy sectors in Southeast Asia.
At the exhibition, we will present our integrated solutions including biomass boilers, industrial steam systems, and full power plant EPC services. Our products emphasize:
Event Details
Date: November 5–7, 2025
Venue: Jakarta Convention Center, Indonesia
Booth: B1-08
We welcome industry partners, plant owners, EPC clients, and technology scouts to visit our booth and explore collaboration opportunities. Whether you are planning a biomass retrofit, a new power plant EPC project, or seeking high-efficiency boiler equipment, our engineers will be available for technical discussions and project consultations.
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