Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.
How to trouble shoot circulation issues for a hot water boiler
in Gas Heating
I have a residential crown cxe 5 boiler with a grundfos type up pump. I am getting inconsistent heating. I suspect that there is a circulation problem because when a thermostat calls for heat, the boiler comes on, but shuts off prematurely. On shut-off, the water temp is about 200 F, which I think is the limit temperature. The pump and pipes sometimes feel like water is circulating and sometimes not. How do I remove the cover plate on the pump to see it it is turning? Any other thing to check would also be appreciated. Thanks
You would need a meter to verify the unit is getting power. An amp meter could be handy. If you touch the body of the pump is it extremely hot? Can you feel or hear it doing anything?0
I think those are the ones with the cap on the end that takes a large slotted screwdriver. If you pull the cap, you can see the end of the shaft."If you can't explain it simply, you don't understand it well enough"
The only reliable method to check motor rotation on a Grundfos pump, is with this tool.
Thanks guys! Not sure how to attach a comment to a specific reply, but to ICHMB, yes sometime I hear or feel the pump moving liquid, sometimes not. The pump get to be the temperature of the hot pipes, but not hotter.
To Zman, the instructions with a new pump I have say to remove the cover and use a screw driver to turn the pump...but don't say how to remove the cap. I'm afraid to damage the cover.
To Henry, that is really cool. I will check to see If I can get one of those tools.
I have an extra pump I can put in, maybe I will. But Im thinking that maybe it is a controller that is causing the problem. If the one board with the electronic spark connection on it is the logic controller... maybe I should replace it.
Thanks again all. Really helpful comments.0
The pump shown in the picture with the key ring has a large plug about the size of a nickel coin. If yours has that you can unscrew that plug. It is to bleed air out of a pump, assure that the rotor is wet and sometimes with a screwdriver, crank start a stuck pump. I remove them with the pump running and even stick my little finger in to feel the rotor spinning. If the pump is stuck then use a fair size screwdriver to rotate the rotor for starting. Water should drip out when the plug is loosened.
The pump rotor needs water for lubrication.
If you have a spare pump you could remove the plug on it and look inside for the slot to put the screwdriver for the "jump start". The dry pump may not rotate as easily as the wet pump will.1
Oh right. I like to live dangerously, but not that dangerously!JUGHNE said:
.... even stick my little finger in to feel the rotor spinning. ...Br. Jamie, osb
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England0
Jughne. Thanks. Ill try to unscrew the plug.
As a final point, can anyone educate me on what component/board controls the pump... or how that logic works. If there is a board I can replace, maybe that next.
Thanks again to all.0
- 121.3K All Categories
- 84K THE MAIN WALL
- 2.9K A-C, Heat Pumps & Refrigeration
- 53 Biomass
- 417 Carbon Monoxide Awareness
- 40 Chimneys & Flues
- 1.7K Domestic Hot Water
- 4.8K Gas Heating
- 119 Geothermal
- 155 Indoor-Air Quality
- 3K Oil Heating
- 56 Pipe Deterioration
- 772 Plumbing
- 5.4K Radiant Heating
- 362 Solar
- 14K Strictly Steam
- 3K Thermostats and Controls
- 51 Water Quality
- 627 Buy, Sell, Barter
- 38 Industry Classes
- 73 Job Opportunities
- 19 Recall Announcements