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This pump has a coupling device between the motor and the impeller.
Boiler Circulation Problems | Troubleshooting Hydronic Water Loops – Richard, we have a hot water boiler and we are having problems with the circulation of the water. The radiators are cool and we don’t seem to have good heat. The boiler seems to be working fine but the radiators are cool. Can you give me some insight into my boiler circulation problem? Kate
Boiler Circulation Problems | Troubleshooting Hydronic Water Loops
Kate, there can be several things wrong that keep the water from circulating through the water loop. The first place to start is the circulator pump. This should be located near the boiler in the near boiler piping. I would check the aquastat to make sure it is engaging the circulator pump as the aquastat has a relay that turns the circulator on when there is a call for heat and the temperature inside the jacket is the right set point temperature according to what the aquastat is set for in temperature ranges.
The best way to do this is with a multi-meter to make sure the output to the pump is 120 volts. Most pumps for residential systems work off of 120 volts. If you have 120 volts on the terminal connections where the wires go to the pump then the aquastat is good and the relay is working as it should.
Now you should check the pump. You want to know if there is flow going through the pipe from one side of the pump to the other. As always, when dealing with electricity always use basic electrical safety procedures. Electricity is dangerous especially for someone who knows nothing about it. When in doubt, call a professional.
Boiler Circulation Problems | Troubleshooting Hydronic Water Loops
Some pumps have a linkage or coupling device. This device connects the motor to the bearing assembly where the impeller is located. The impeller pushes the water through the pipe and some pumps do not have coupling devices but are direct drive. In other words, the pump motor is directly attached to the impeller with certain pumps. Pumps with coupling devices need to have the coupling device inspected to make sure it is not broken. If the coupling device is broken it needs to be replaced and that was your circulation problem.
If it is a direct-drive circulator pump then you need to inspect the impeller to make sure it is good. Impellers do go bad from time to time and need to be replaced. If this is the case, you should really call a boiler technician to fix the problem.
Furthermore, many will have the parts on their truck and can have you up and running in an hour or so. They will also know the correct procedure for replacing the impeller without causing additional problems which if you really do not know what you are doing you can cause additional problems. Other problems with the circulator can be a bad motor or a leaking bearing assembly. Some circulator pumps require maintenance while other pumps are maintenance-free.
Boiler Circulation Problems - Air Problems and Troubleshooting
Automatic Air Vent or Automatic Air Bleeder
The next thing that can cause the water not to circulate in the water loop including to the radiators is a hydronic airlock. This is when you get air into the loop. Air will build up usually on a riser or in a radiator. It is necessary to remove the air from the system. Many radiators and even baseboards have manual air bleeders on them. The air bleeders require a key to open them and hopefully, you have an air bleeder key.
If you have an air bleeder key then you can go around to all your radiators and open these air bleeders with the key. Furthermore, air management in your boiler loop systems is important. Finally, it could also cause boiler pressure problems causing your pressure relief valve to vent.
Take a rag with you and open the air bleeder until you get water. In some cases, you will get water only and in other cases, you will get lots of air. Let all the air bleed from the system. As much as possible. Your system should also have automatic air bleeders or automatic air vents located somewhere in the loop. Typically these are located on the risers of the piping.
Furthermore, they automatically vent any air that gets into the loop. They are usually very reliable and need little maintenance. However, from time to time they can stop working and need to be replaced. Again if these need to be replaced an HVAC technician should replace these.
Boiler Circulation Problems | Troubleshooting Hydronic Water Loops | Conclusion
One last thing you can check if you have circulation problems is the shutoff valves in the piping. If someone haphazardly played around with one of these valves and turned it off then you will definitely not have the flow going through the water loop. Check to make sure these valves are open. Hopefully, it is as simple as opening a valve but probably not the case. Good Luck to you and I hope your problem gets solved soon.
Boiler Circulation Problems | Troubleshooting Hydronic Water Loops
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Heated my shop with closed loop radiant heat for years. Heat supplied by a Hardy boiler. I changed my heat source to an LP fired tank and used the same type of pump(taco 009) to circulate system. Not getting heat circulation. No blockage, no air in system, can you help?
without looking at it I couldn’t say.
Having problem with air in furnance pipes.Replaced a zone valve which was bad but still have excessive air in radiator lines.When the heat comes on in the morning the pipes sound like a river running through the house.Bled the lines for upstairs, since this is where the air is making the noise.There is no problem with the downstairs heat.Could the circulator pump be at fault,maybe not pushing the water through the pipes.The circulator pump is about 7 years old.Every morning when heat is required we hear water running through the pipes upstairs.It actually sounds like a river.
Really can’t say for sure but I would start with the expansion tank and make sure that is good first. Also, the temperature settings need to be within the limits. Then bleed all the air out manually (sometimes this requires hooking up a water hose to the system to give it a clean flush) and then test the system. If you can hear the circulator pump running I doubt it could be the problem but then it should be tested to make sure it is not. Again, the system needs to be thoroughly checked to eliminate the problem.
We have a radiant heating system. Our propane tank went to empty due to weather and travel. No pipes froze. We have restored the propane but now we find that our radiant heat demand miximizer will not stay on. We can call for heat, the radiant goes on for a few minutes and then shuts down again.
We live in the NE and it’s been very cold, but our house (weekends only) doesn’t get below 50 degrees inside, which is what we’ve set our remote thermostat to.
Why doesn’t the miximizer stay on?
Could be a bad temperature sensor or the settings are somehow out of whack from what they should be. The settings, in this particular pump, are done with dip switch settings. I would recheck the settings and the temperature sensor. If you don’t find anything wrong then you likely need to call an HVAC company to come out and check things out. The temperature sensor, if it’s a 10K thermistor, needs to have 10K ohms of resistance at ~70°. That can be tested with an Ohmmeter or multimeter set to Ohms. Don’t forget, if it is not installed in a temperature well, it needs to be securely strapped to the pipe and insulated well.
What about frozen or restricted lines????
Frozen lines need to be thawed obviously and the lines should never become restricted provided a decent water quality. If the pipes froze up you will likely be replacing some of that pipe. I never really seen hot water boiler piping get restricted lines but steam boilers have that problem. It is why steam boilers need to blown down or flushed weekly during the heating season.
can our boiler be converted from a non direct drive to a direct drive we have had the bell and gusset and plastic impeller replaced twice within 2 months from a local company . its in our rec center in a mobile home park
sure but even a direct drive has an impeller so you could possibly experience the same issue. You need to find out what’s causing the impellers to go bad,.