What to do if the Boiler Circulator Pump wears down

When we talk about a boiler, we are usually saying a wall-hung gas boiler(combi boiler), that use hydronic power—the power of water—to circulate heat to radiators and baseboard heaters that send out clean, dust-free warmth into rooms.

An essential component of a boiler is the circulator pump, which sometimes needs repairs to keep a boiler running.

Without the boiler circulator pump, the hot water in a boiler would have trouble moving through the pipes to the terminal points to send out heat. Convection currents from heat would move the water along the pipes, but at only a fraction of the power. The circulator pump contains an electric-powered impeller motor that removes the hot water from the tank to circulate through the pipes to the baseboard heaters or radiators. At the same time, the boiler pump draws in cold water to start the heating cycle.

If a boiler circulator pump wears down, it can begin to cause problems. An overworked pump can cause circuit breakers to trip, which is often an early warning sign that the pump needs repairs. Broken inside components and valves can cause the pump to stop working. A pump can also develop leaks because of corrosion, and this will cause the water pressure inside the tank to drop and reduce the heating throughout the house. A leaking pump or one with interior damage usually must have a replacement.

Replace the boiler pump head only

A boiler circulator pump is made up of two parts, pump head and pump housing(pump body). The pump housing is usually made of plastic material in different shapes that are used to connect the boiler pipes and other boiler components with the boiler pump. It also has an air vent valve. If you make a full replacement of the boiler pump, all these pipes and components fixed on the housing must be disassembled. Besides, you have to find a boiler pump with the exactly same housing with your old one. It takes time and complicated work and spends you more money.

However you can also choose to keep the old boiler pump housing, and just replace the pump head only. Then you just need to unscrew the four bolts that bind the pump head with the housing for replacement. It saves your time and money.

As the plastic pump housing is simple and not easy broken, it is not necessary to be replaced in most conditions. So there is only one thing left for your consideration. Which pump head could be used for replacement?

Obviously it is much easier to get a suitable pump head, compared with a complete boiler pump. Boiler pumps differ in the plastic housings, but the pump heads are compatible among their own brand boiler pumps. What’s even better is that Plastmax’s pump heads can also fit the Grundfos and Wilo boiler pump housings. So now you have more choices to replace your old boiler pump head with a new one in a good price.

Replace the boiler pump rotor only

In some cases, even the motor and electric part of pump head are still good to work, but only the shaft and bearing of pump rotor have been of abrasive wear by limescale and black iron oxide particles present in heating systems and causes pump seizure finally. Then what you need to replace is only the rotor kit(including the rotor and shield cover). It is the most cost-saving way to repair a boiler pump. But different from replacing the pump head, it is not easy to find a rotor kit compatible with your boiler pump. Fortunately Plastmax also supply rotor kits that fit Grundfos boiler pumps.

Different from the high expensive original parts of Grundfos or Wilo pumps, Plastmax supply those compatible boiler pump parts in reasonable prices. Believe it or not. Just contact us for a quotation.

Related products


OEM circulator pumps fit for wall-hung gas boilers of world brands like Vaillant, Viessmann, Bosch, Italtherm. Due to its excellent compatibility, it is the best choice fit for replacement of older circulator in gas boilers. High efficiency type is also available.


Flow max
Head max
Liquid temperature
Pressure max

2.3 m3/h
7m
2.. 95°C
3 bar


Designed for heating, domestic hot-water, cooling and air-conditioning systems. The pumps are available in various materials, making them suitable for a range of applications. Reliable and maintenance-free. No noise.


Flow max
Head max
Liquid temperature
Pressure max

9.6 m3/h
15m
2.. 110°C
10 bar


High efficiency circulator pumps of compact design, suitable for all HVAC applications, from boilers and heat pumps to Heat Interface Units (HIU) systems. It is controlled with all basic functions and also PWM function for remote control.


Flow max
Head max
Liquid temperature
Pressure max

4.0 m3/h
8m
2.. 110°C
10 bar

Pump-HES25-6
High-efficiency circulators, designed for heating systems. Applicable as a universal upgrade and replacement pump. The pumps are available in various materials, making them suitable for a range of applications.


Flow max
Head max
Liquid temperature
Pressure max

3.7 m3/h
7m
2.. 110°C
10 bar