A boiler's circulator pump is used to remove hot water from the boiler, and then pass it into heating devices such as the radiator or a convection pipe system. The power of the pump is enough to cause the water to travel right back up to the boiler from the pipework. Using a circulation pump is a great way of keeping water traveling throughout the system. Some large homes even use a number of pumps together to warm specific areas of the house.
Despite their usefulness, like all mechanical equipment pumps can sometimes fail, and when this happens, you need to be able to troubleshoot your heating devices. To troubleshoot the circulator pump, you will first need to make sure that the boiler is already hot (if not, it is a thermostat problem), but the hot water is not being moved out of the tank. Wait until the boiler temperature reaches the required level at which the pump should cut in, and then check the device.
Here are a few common circulator pump issues.
1. Pump Is Not Running
If the pump is not running at all, this implies that the hot water is not entering the pump system, or heat is traveling there very slowly. Your pump may be very quiet, but if no water is being moved through the system, this implies that there is no power in the pump. Valves or other parts inside could be damaged, in which case you should turn off the pump, and have it replaced by an experienced plumber. The pump may also be too small to push against the water pressure. In order to fix the latter, you will need to increase the amount of cold water pressure or purchase a larger pump.
2. Pump Is Noisy
Most circulator pumps are silent. If you are hearing a lot of noise from the system, this can mean that you have an excessive amount of air located in the pump. Purging the pump should cure this, but if this does not stop the noise, then you may have a bearing, a part of the pump's internal mechanism, which has come loose. This will mean that the pump needs to be replaced. Tilt the pump from side to side, and listen for any rattling or clanging sounds.
3. Pump Is Leaking
Pumps often develop leaks at joins or flanges points. This is due to the pressure of the water penetrating the weakest parts of the pump, and also the weight of the pump itself affecting joins and causing holes through which the water can penetrate. Leaks can cause loss of water pressure, and may affect heating in parts of the house. This problem is not difficult to spot on the pump itself, as there will often be staining along the outside of the pump, and pools of water on the floor below. Caulking around the joins and flanges may help to solve the problem in the short term.
With this guide, troubleshooting your boiler's circulator pump is easy. When in doubt, you should call an experienced plumber.