Boiler reaches high limit within minutes, then shuts off
Comments
-
Just because you hear humming, doesn't mean the circulator is circulating water.
Is the water coming back to the boiler (about 10 feet away) almost as hot as the water leaving the boiler (also about 10 feet away)?There was an error rendering this rich post.
0 -
Double check, please. If you close the red valve and then open the drain spigot, no water comes out? And if you then open the red valve -- change nothing else -- then water does come out?
If so, then indeed water can't circulate. Don't try to run your nice new pump -- you'll likely ruin it. Instead, trace all your pipes carefully and see if somewhere, lurking in a corner, there is a valve on either the hot water feed to the radiators or the cool water return which got closed somehow.Br. Jamie, osb
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England0 -
I have not checked more than a couple of feet away and I figured that the return pipe would be hot just due to convection.STEVEusaPA said:Just because you hear humming, doesn't mean the circulator is circulating water.
Is the water coming back to the boiler (about 10 feet away) almost as hot as the water leaving the boiler (also about 10 feet away)?0 -
I'm pretty sure that is the case but I will double check tonight. I can't imagine any other valves anywhere else in the system other than in the boiler room.Jamie Hall said:Double check, please. If you close the red valve and then open the drain spigot, no water comes out? And if you then open the red valve -- change nothing else -- then water does come out?
If so, then indeed water can't circulate. Don't try to run your nice new pump -- you'll likely ruin it. Instead, trace all your pipes carefully and see if somewhere, lurking in a corner, there is a valve on either the hot water feed to the radiators or the cool water return which got closed somehow.0 -
Point is, if water can circulate then it doesn't matter whether the red valve is opened or closed when you open the spigot -- water should come out.fuentesfern said:
I'm pretty sure that is the case but I will double check tonight. I can't imagine any other valves anywhere else in the system other than in the boiler room.Jamie Hall said:Double check, please. If you close the red valve and then open the drain spigot, no water comes out? And if you then open the red valve -- change nothing else -- then water does come out?
If so, then indeed water can't circulate. Don't try to run your nice new pump -- you'll likely ruin it. Instead, trace all your pipes carefully and see if somewhere, lurking in a corner, there is a valve on either the hot water feed to the radiators or the cool water return which got closed somehow.
Another possibility -- other than a closed valve -- is that your system for some reason doesn't have enough water in it to rise from the boiler up to your radiation, then flow around and come back down. Hard to believe that is the case, but... the comment you made about the pressure dropping when you open the autofill valve by hand does give me pause... doesn't make much sense.Br. Jamie, osb
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England0 -
How about a picture of your new pump? Both sides and the nameplate.0
-
Did you make sure the new pump is installed in the same direction as the old pump? You can't go by the way the control box is positioned because it may have been rotated when the last person installed it. If it has a check valve in it, that would stop the flow if you are trying to feed it backward.
And make sure you have at least 8-12 psi for boiler pressure.
Rick1 -
is this a single zone? does the thermostat come back to the boiler control?0
-
How much water did you flush out of the boiler drain before the red valve with the red valve closed and the fast fill open? You may have air trapped in that loop from when you replaced the pump that you need to purge out. It may take several gallons.
What pressure does the system come up to when you close the fast fill and let it come up to pressure?
by "the temp and pressure goes down" you mean the pressure goes down as soon as you open the fast fill valve, or the pressure actually went down when you opened the boiler drain before the fast fill valve?
It kind of sounds like the pressure reducing valve or water supply is not keeping enough pressure in the system to keep the air out and keep it circulating.0 -
How much water did you have to drain to replace the circulator?
0 -
We need pictures gol dern it.0
Categories
- All Categories
- 85.9K THE MAIN WALL
- 3.1K A-C, Heat Pumps & Refrigeration
- 52 Biomass
- 420 Carbon Monoxide Awareness
- 78 Chimneys & Flues
- 1.9K Domestic Hot Water
- 5.2K Gas Heating
- 94 Geothermal
- 154 Indoor-Air Quality
- 3.3K Oil Heating
- 59 Pipe Deterioration
- 884 Plumbing
- 5.9K Radiant Heating
- 378 Solar
- 14.6K Strictly Steam
- 3.2K Thermostats and Controls
- 51 Water Quality
- 41 Industry Classes
- 47 Job Opportunities
- 17 Recall Announcements