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[MD20/20]

no problems with pump, did have a drip from threaded pipe which shorted out the blower.  all good now.  It was good to take it apart on a warm day;  if it was cold, I would have been whining.

[allis48]

I had to rewire mine to bypass the thermo cut out on trhe coldest day of the year at 1030 at night I wasn't happy

[RSI]

Looks like the pl36 might be a tight fit expecally when you try cramming 2 of them in there

They aren't that much bigger. Just a little longer motor.

[allis48]

Is the increase in flow going to hurt anything? I am running the one for the house on low and the building on medium, don't know if that will cause backpressure that would be hard on the pumps or not.

[RSI]

If you are only running it on low you might want to consider a Grundfos 15-58. They are only around $100. The pumps that come on the NC boilers appear to be Grundfos knockoffs but there isn't a Grundfos with the same specs as the NC pump.

Nature's Comfort claims you will burn less wood leaving the pump on high because of the way the return water is routed it can pull more heat off that is going up the chimney.

The PL36 pumps actually seem to like being restricted. The watt usage drops and they get quieter. (less watts should mean cooler running motor)
The one I have running at my house is using about 175 watts and if I close the valve down drops to about 130 with completely restricted. I have pex-al-pex so if you have normal 1" pex a PL36 will probably use 150-160 watts.
I have heard numbers from 245 to 285 watts that the NC pumps are drawing on high speed from people that have put meters on them. The lowest I have heard on low is 205 watts. That is what made me finally decide to not get any more.

If you have a pump using 100 less watts and you are paying $0.10 per KWH you will save over $7 per month. At $40 a year the pump will pay for itself in a few years.

[allis48]

I have a 200,000 btu heat exchanger in the building and the one for the house is I think 104,000. So what do you think would be
the best setting? I ran them both  on high before just seems noiser.The whole system even the exchangers are 1".

[RSI]

Since you have 2 pumps you will have more water flowing back into the boiler on the lower settings than one pump would on high. I would turn on the blower and then feel how much the return pipe cools on the different settings. Just grabbing the pipe will get you a good idea on the temperature.

How many feet of pex are in each loop?

[allis48]

garage is 30-35 feet house is 100feet it is about 30 degree drop from inlet to outlet. I am going to get one of them pl36  pumps I think just to have a spare found them for $208 shipped

[RSI]

I could sell you one for $205 shipped if you want. Lol

[allis48]

If its new which I believe it is its a deal. You been a big help with all my newbie question is beats buying it from ebay

[RSI]

Yeah brand new in sealed box. I have to buy them in batches of 5 to get good pricing so I keep them on the shelf.

[johnybcold]

My ears are perking up about this filter, are you saying you have a filter on the supply or return line from them boiler? If so it sounds like a nice project for me, I am using well water , when I check the level it seems pretty clean but last time there was something floating in it

[RSI]

Way back (8 or 9 years ago.. lol) when I bought my first outdoor boiler they made me buy a filter or they would void the warranty. (Pacific Western brand, turned out the warranty was no good anyway)

They sold me a Rusco spin down filter. It was only a 3/4" so restricted the flow a little. I have had it bypassing for the last couple because it seemed to be restricting the flow a lot more and cleaning the mesh filter didn't seem to help much anymore.
I didn't know what was the correct replacement filter so never replaced it but I just set up an account at a new supplier that carries them so will order one next time I get stuff from them. They also have 1-1/4" models.

They are pretty expensive though. I think I paid close to $200 when I got mine but if I decide to start selling them the 1-1/4" will probably be around $150 and 3/4" $20 or $30 less.

Depending on what you are trying to catch, you might be better off with a $25 Y strainer.

I used to always recommend Y strainers to everyone with plate heat exchangers but then started running into problems with people not maintaining them and found it was less trouble to leave them off.
If you are going to keep it clean it probably is a good thing to have.

[Hydronix]

After having so many failures with the same pump, I would definitely look for other options. Taco and Grundfos are all that is used around here until we get into commercial or industrial and even then its still Taco mostly, no one likes call backs. What is the pH of the water? Doesn't matter what speed or size pump you have the head will determine how much gpm you will flow. To large a pump and you could create cavitation and burn the pump up. 10 gpm will supply 100,000 btu/hr at 180*. Wet rotor or dry, improper application/size will always use more electricity, especially on cheaper pumps.  A 007 on 1 1/4" P-A-P pipe will flow more gpm and use less electricty than say a 0012 or 0014 on a 1" pex header. It always takes more money in the begining to save money long term. Pumping glycol takes 10-30% more energy and flows 10%+ less gpm compared to water. Any of those pumps should not have any worn parts in that short of time ( 3 in 1 year) without defects or highly corrosive liquids present, which glycol is, in open systems to brass and copper. Todays pumps are much better than those of 20 years ago, so cycling them is fine, they don't have to run constantly if they are sized correctly, this is usually a sign of undersized pipe or pump.  If you add a filter, especially those spin off types, make sure you calculate the head loss as many will require 2 sizes larger pump. There are some with very low head loss , but at a considerable price. Good luck on finding the root cause.....