Primary Boiler Pump Failure?

Reply

  #1  
Old 07-06-13, 08:10 AM
J
Member
Thread Starter
Join Date: Jul 2013
Location: usa
Posts: 6
Received 0 Votes on 0 Posts
Primary Boiler Pump Failure?

I think I have a primary boiler pump failure. The pump is getting really hot but the impeller is not turning (i.e. it is not making the regular humming sound when it is pumping). So the boiler is overheating and faulting off due to no circulation. The temperature and pressure soars in the boiler than shuts off showing F2 on the vitodens 100-W.

1) Does it sound like a pump failure?
2) How easy to replace? It looks easy. Just turn off main power switch to the system, close the valves above and below the pump, unbolt the pump and disconnect the electrical line to it somehow. Am I correct? It is a Taco Cartridge circulater model 007-F5.
 
Sponsored Links
  #2  
Old 07-06-13, 09:56 AM
G
Member
Join Date: Oct 2008
Location: USA
Posts: 2,967
Received 10 Votes on 10 Posts
First, I would isolate the pump and remove the cartridge to see if you can figure out what is wrong. Remove the four capscrews, and the cartridge can come out. Maybe there is something wrong with the cartridge, which is the only moving part - which would be cheaper and easier to replace than the entire pump.

If the cartridge turns freely in the pump, then I would suspect a problem with the capacitor, which is simple to replace. Otherwise, it could be a problem with the electrical stator windings - if so, the pump is shot.
 
  #3  
Old 07-06-13, 12:24 PM
J
Member
Thread Starter
Join Date: Jul 2013
Location: usa
Posts: 6
Received 0 Votes on 0 Posts
Ok I will try that but first can you let me know if based on what I told you, the pump is the problem. The pump is only 7 years old, don't they last longer than this or because the primary pump is operating the most, it is the first to die?
 
  #4  
Old 07-06-13, 12:45 PM
G
Member
Join Date: Oct 2008
Location: USA
Posts: 2,967
Received 10 Votes on 10 Posts
If there is no flow noise, then I would suspect the pump. Yes, those wet-rotor pumps normally last a long time, more than seven years - there is little to go wrong. What does the boiler pressure gauge read? Are you sure the system is full of water?
 
  #5  
Old 07-06-13, 02:12 PM
J
Member
Thread Starter
Join Date: Jul 2013
Location: usa
Posts: 6
Received 0 Votes on 0 Posts
18 PSI I briefly open the 3 drain points on the system and water immediately came out and pressure went down. When I fire up the boiler, temperature and pressure rise rapidly and then go too high and the boiler shuts itself down with F2 fault. The inlet to the pump gets warm but the outlet is cold. The pump itself gets very hot.
 
  #6  
Old 07-06-13, 03:32 PM
G
Member
Join Date: Oct 2008
Location: USA
Posts: 2,967
Received 10 Votes on 10 Posts
Pull the rotor from the pump and inspect it. After you get the pump problem resolved, you may have a second issue - the rapid rise in pressure suggests that your expansion tank may be waterlogged.
 

Last edited by gilmorrie; 07-06-13 at 05:38 PM.
  #7  
Old 07-06-13, 05:40 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
It does sound like a pump problem to me...

Also:

temperature and pressure rise rapidly and then go too high and the boiler shuts itself down with F2 fault.
What does the boiler manual say that in F2 fault is?

Do BOTH temperature AND PRESSURE rise rapidly? Where does the pressure start when cold, and how high does it get before the boiler shuts down?

You might also have trouble approaching with the expansion tank if the pressure goes high...
 
  #8  
Old 07-07-13, 05:40 AM
J
Member
Thread Starter
Join Date: Jul 2013
Location: usa
Posts: 6
Received 0 Votes on 0 Posts
their manual says 1) check pump operation, 2) check water level (like I said seems to be full of water) and 3) vent system of air (don't think that is the problem).

Yes both rise rapidly. Temp goes from 150 to 230, pressure from 16 to 24 or 25 then shuts down with F2 Fault
 
  #9  
Old 07-07-13, 09:47 AM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
From 16 to 25 isn't an unusual pressure change for that amount of temp change, but it's always wise to service the expansion tank at lease bi-annually... by service I mean check the air charge and adjust as necessary (presuming that you have a bladder type tank).

If you haven't already, read this:

http://www.doityourself.com/forum/bo...sion-tank.html

and this:

http://www.doityourself.com/forum/bo...ure-gauge.html

It does sound like your 'bottom line' problem is your pump though... take gilmorries advice.

Did you tell us the make/model of the boiler ?
 
  #10  
Old 07-07-13, 01:19 PM
J
Member
Thread Starter
Join Date: Jul 2013
Location: usa
Posts: 6
Received 0 Votes on 0 Posts
Ok thanks for help. I will keep you updated. It is Vitodens 100
 
  #11  
Old 07-11-13, 03:40 PM
J
Member
Thread Starter
Join Date: Jul 2013
Location: usa
Posts: 6
Received 0 Votes on 0 Posts
Primary Boiler Pump Failure?

Success!

It was in fact the primary pump.

I replaced the pump and the system is working fine now.

I bought the Taco 007-F5 pump on Amazon for $84.99 and "free shipping" and no tax. It took 5 days to arrive. No hot water for 5 days = angry wife and kids. LOL

To install, I killed the main power switch to the system. Then I shut the valves above and below the pump so I didn't have to drain the system. Disconnected the wires by cutting the power supply wires (they were crimped on to the pump wires). Unscrewed the ground wire. Then I cut off 1/4" of the coating on the wires to expose them. Unbolted the pump and a little residual water in the pump came out, about 1 cup. Then I put the gaskets in the grooves of the pump flanges and carefully slid the pump in place (motor must be parallel to the ground) while ensuring the gasket stayed in place. I hand tightened all 4 nuts and bolts. Then I wrench tightened them. Then I connected the ground wire to the pump using the screw on the pump. Then I connected the white power wire to the white pump wire. I connected the colored power wire (black) to the colored (yellow) pump wire. I had no crimps and no crimping tool but I had the screw on wire caps so used those to secure the wires together. Then I closed up the wire box. Then I opened the upstream and downstream valves on the pump and heard a quick little rush of water filling the pump cavity.

Then I threw the power switch on. The pump immediately started and so did the hot water pump. The united ignited and interestingly I didn't have to hit the reset button as I expected to have to do. The unit heated up, from 80 to 174 and stopped there where it is supposed to, pressure remained constant at about 14 PSI. This time the main circulation pipes all got hot and I could hear a faint hum from the pump. I checked for leaks and there were none. Once the hot water tank was hot the hot water pump stopped and the boiler then cycled off so everything is working fine!

One minor concern was when took the cover off the Vitodens 100 I noticed a small puddle in there. I wiped it up and saw no leaks. I am going to assume that this was caused by when I shut the unit down it cooled from 200 degrees to basement temp of 60 degrees and sat there for 5 days so condensation formed on the outside of the pipes and then dripped down.

Someone asked me to use an amp to test the old suspect pump but I don't have one.

Someone suggested replacing the cartridge instead of the whole pump but I was told that would cost a big percentage of the 84 bucks I paid for a brand new pump.

Thanks for your help people!
 
Reply
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: