15-Second Fix: Is My Pump Working? I Need to Know!

We have had several callers recently tell us they thought that their pump was not working.
How did they know? They were NOT SURE!
Here is how you can know for sure whether your pump is running – your pump IS WORKING if you have the following conditions: 

  • Hot Tubing - If the outdoor boiler is hot, then feel the PEX tubing in your basement. If it is hot also, the pump is working, at least partially.
  • Warm Enough? - Are you getting enough heat and hot water? If yes, then there is no problem! But if your PEX pipes are warm, and you are NOT getting enough heat, then you should first try to turn up the setting on the pump. Our pumps have three speed settings – first try the slowest speed (“1”), but move that up if that setting does not get you the heat you desire.
  • Water Flow in Filter? - Clean your filter. Once you complete this and open the valves to allow water to circulate back through the filter (and close the bypass), you should see water flowing through the filter.
  • Shaft Spinning? - On our strong “Brute”pump, there is a silver button on the front name plate. REMOVE that button with a flat head screwdriver. A small amount of water will dribble out – that is normal. (If there is no water, then you may have an air lock or a ball valve closed preventing the pump to do its job. Do NOT allow this to happen!) Now using a Philips head screwdriver, touch the pump shaft. If the pump is running, you will hear and feel the vibration of the shaft spinning.

If any of the above conditions are not met, your pump is not circulating water.  Here are the possible reasons and solutions: 
  • A ball valve is closed somewhere in the system. Easy fix!
  • Your filter is clogged. Easy fix! If needed, you can obtain a new filter cartridge by clicking HERE.
  • Your pump is air-locked - Make sure the pump is installed so that the shaft is level (see photo >>>). An air locked pump will run dry and eventually overheat and fail.
  • No Filter - If you never installed a filter in your outdoor boiler system, your heat exchangers may be plugged from sediment. The solution is to install a filter kit (available HERE). If sediment buildup is significant, you may need to replace your heat exchanger(s).  This is why 98% of my customers use filters. Without a filter, it is only a matter of time before the heat exchangers fail.
  • Not enough pumping power - If you do not have enough pumping power, or if you are asking the pump to do more work than it is designed to provide, then you have the wrong sized pump, or not enough pumps installed. Your pump may appear to operate properly, but will eventually fail if under-sized. See our blog article on proper pump sizing by clicking HERE.
  • Old Age – Pumps die and will need to be replaced eventually. Your outdoor boiler is designed to outlast all of its electronic components. Remember to replace your pump only with the specific Grundfos pump that meets the specifications of outdoor boiler hydronic use available HERE.

By using the proper pump, your system will give you the most efficient, warm heat and save you the most money on your heating bills for decades!