DIY replacing heater boiler furnace circulation pump. Grundfos

She was a dark and cold (10F) nite :)
Woke up to colder than usual basement. Sat morning. Quick troubleshooting s howed functioning Tstat, good wiring to boiler's control box. Swapped relay s (I have 2 zone system), for JIC, nada.
Pump showed 110V on terminals. Swapped the start cap from the working pump. Nada, no noise of running water, dead quiet boiler.
Started calling local plumbers. Vague quotes of $300-400 for new pump (!), 100s more for labor. And I'd have to wait till Mon - meaning I'd need to so mehow keep the basement warm, while pipes in the walls, exposed to cold, wo uld prolly freeze over.
Being a handy type, looked up replacement part on Amazon. Being prudent, or dered 2. If 1 failed, second one is not far behind. Under $100 per, Grundf os. Ordered for Sun delivery. Kudos to Great River, they showed up nice and early.
Replacing was real easy. Power off. Shut off valve above and below the pump to OFF. 4 flange bolts. Put a roasting pan under the old pump as I remove d it, may be 2 cups of water came out. Open the valves back.
Note that some pumps come with a check valve that needs to be removed prior to install. My didn't have it. Do RTFM
New pump has spring terminals (yay!).
Started up the furnace. Some very faint noise came out of the new pump. Hmm . This: http://www.harborfreight.com/digital-clamp-meter-96308.html showed 2.5A draw. Way too much for 1/25 HP pump. The pipe up/down stream of the ne w pump stayed luke-warm. Clearly there was a blockage in the line.
After few minutes pump got hot to touch, so I turned the system off.
Clearly I had dreaded ice aka frozen lines.
Got the basement as hot as possible. Used hair dryer to heat up whatever se ctions of the heating pipes I could get to. kept cycling boiler every 20 mi n or so.
Well, it took over 2hrs of that and just before I was ready to throw in the towel, success. She sounded like Niagara when water finally started to flo w. Current draw went down to .7A. That's more like it !
That and the pipes up and down stream of the pump finally got hot.
So the moral of the story:
- anyone can handle the replacement job
- for JIC, if your pumps are more than 4 years old, pre-emptively order a r eplacement and have it handy. They WILL quit, eventually. Helps to be prepa red.
- Amazon has EVERYTHING and I mean EVERYTHING. Before you let a local trade r@pe you, see if you can buy what u need there. For lots of areas they do 1 day delivery, even on Sundays
- even if u have an alert system that would go off when temp drops, what wi ll you do when a pump quits on you @ 1am on sub-zero Sat morning ? Unless y ou have a replacement pump, there is 95% chance of pipes freezing before ne w pump could get installed, EVEN if you manage to keep the area warm. So, d o order a spare
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RK wrote:

I did one for a customer a few years ago , his didn't have cutoff valves above and below , we dumped several gallons before we got the nrew pump in place . His wasn't dead , but had been leaking for some time . I wish now I'd kept the old pump , he offered . Motor woulda come in handy more than once !
--
Snag



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Amazon is even better (or worse, depending on your perspective) that you think. They have a division that will give Grainger a run for their money. http://www.amazonsupply.com/
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wrote:

I did maintenance for a large building that had a boiler and had 4 or 5 of those pumps. (Zone heating). When the first one failed, I got two of them, so we always had a spare. But I also got rebuild kits. Most of the time the pump impeller and/or bearings failed, but the motor was fine. Changing the pump was simple. 4 bolts and the wires. Rebuilding one was not all that hard either. I would rebuild them when I didn't have much other work to do. That way I always had at least one spare that was working. The impeller kit had some ceramic sleeves that served as a seal. I thought that was strange, but it worked, and the pumps lasted quite a long time for as much as they ran.
While reading this post, I'm trying to remember the brand name of those pumps. The same company made almost all of them, but it's been 30 years since I worked there.... I cant remember! I know they were red.
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On Monday, January 12, 2015 at 8:30:50 AM UTC-6, snipped-for-privacy@spamblocked.com wrote:

Red are Grundfos and green are Taco brand...
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On 1/12/2015 8:31 PM, bob_villa wrote:

- . Christopher A. Young learn more about Jesus . www.lds.org . .
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RK,

Congratulations on the successful pump swap!
It sounds like you had issues with frozen pipes, but a similar situation can occur if there is air in the line. Most of these pumps are not self priming. You typically need to have a drain valve on the outflow side of the pump so you can drain off the air until water is in the pump. Then shut off the drain valve and start the pump.
Anthony Watson www.mountainsoftware.com www.watsondiy.com
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snipped-for-privacy@spamblocked.com posted for all of us...

Red are also Bell & Gosset(sp)
--
Tekkie

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