# What size circulator?



## woodchuck2 (Feb 27, 2008)

Yesterday i did some much needed maintenance on my outdoor wood boiler after the manual damper handle broke off. Every year for the last 3 yrs when i fire up the boiler shortly afterwards a piece of pex will break and need repair. So this yr i opted to replace all the pex and repair the damper while it was shut down for the day. After all of this repair i flushed the lines back to the boiler and fired it up. The circulator seemed air bound and would only push about 10'. I thought maybe it was bad so i replaced it, both were Taco 007-F5's. I had to keep turning off the circulator and back flushing the feed line, then the return and eventually i back flushed both and it began pumping hot water to the heat exchangers. The hole lope distance is about 90' so i find it hard to believe air would stop its pumping. 

My mother lives in this house and she frequently complains of the boiler not putting out enough heat. I have checked the aquastat and that works fine, i have turned it up to 190deg and the lines are hot as hell going as far as the heat exchanger in the furnace, the return is quite cool and i would say probably 80-100deg cooler than the feed line. So my thoughts are since this circulator seems to pump at a snails pace is it a possibility that the fan is cooling off the heat exchanger faster than the circulator can heat it? This is also the 4rth circulator in the last 5yrs in a boiler that is 13yrs old. The original lasted 8yrs. Would it be worth while to bump up to a Taco 009 or 010 for faster circulation and maybe it would keep the exchanger satisfied or should i put another 007 in the return side?


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## Tinstaafl (Jan 6, 2008)

Is the manufacturer still in business? If so, I'd try contacting them for recommendations.


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## rex (Jul 2, 2007)

Just one pump on entire system?

How many things is the boiler heating and in what order?


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## woodchuck2 (Feb 27, 2008)

The dealer we bought the wood boiler from is no longer in business although the manufacturer is. The wood boiler is Woodmaster and is 13yrsold now. Cant remember the model number but i know the model has changed although the boiler specs are the same as the new model which is the 5500 " http://woodmaster.com/woodfurnaces_5500.php ". 

The circulator is on the feed side at the boiler, it pushes a 1" line to a 10 plate heat exchanger on the electric hot water tank, from there it goes to the heat exchanger in the hot air furnace and then returns to the boiler. Not sure of the size heat exchanger in the furnace but it is at least 6" deep and a minimum of 24"X24", in fact i am willing to bet it is closer to 24"X30" but i can measure it tomorrow to be exact. 

The Taco 007 is the only circulator at the moment. I was just given an older 3 speed unit given to me that is twice the size but i cannot read any of the specs on the plate so i will try that to see if it makes a difference. It is free so what the heck, worth a shot.


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## Splinter (Apr 5, 2005)

Is it possible that the heat exchanger is plugged with funk? The 007 doesnt have a high head pressure to push through. Is the 3-speed a OOR? They're designed for lots of small diameter tubing in a radiant system, so give a higher head pressure. Try that first before shelling out $$ for a 0011 or 0013.


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## woodchuck2 (Feb 27, 2008)

There is a possibility the heat exchanger is the problem, i have thought of dumping in a couple bottles of CLR and flush everything after a couple days to see if that makes a difference too. I have no flow issue when flushing, but very little flow from the circulator. It is a single speed right now, i am going to try my freebie tomorrow.


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## rex (Jul 2, 2007)

You need a 011 for sure.

I've built dozens of wood boiler systems and the only time ill use a 007 is for a secondary loop.

My personal house I have a 011 at the boiler feeding my house it goes through the water to air for furnace then the water tank after that I have it T'd off to a few pieces of fin tube and some infloor heating that loop is ran off a 007. Then it returns to the boiler. After that I have another 007 feeding the water to air in my barn. Boiler is set at 180 and works flawlessly.

Bigger pump, no doubt.


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## woodchuck2 (Feb 27, 2008)

Thanks, thats what i thought but wanted to be sure. I pulled the new 007 and tried the freebie, of course it was free because it does not work, so back on went the 007 for now. I guess after the holidays i will be swapping it for an 011. Thanks for the input.

I have also noticed that since it circulates so slow that the boiler boils for a bit after shutting down its cycle, willing to bet more flow will cure the boiling too.

Mine was set at 180 but i bumped it up to 190 for now in hopes of keeping the heat exchanger warmer for a little longer to get more heat out of it. Will be dropping that back down to 180 for sure.


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## woodchuck2 (Feb 27, 2008)

Update, friend of mine who has a Central Classic boiler had a spare Taco 014 circulator so he gave it to me to try. Huge difference in flow! The main heat exchanger now keeps pace with the fan, the return side is warmer and the boiler is not getting the water as hot when idling. The home is warmer even after i dropped the aquastat back to 170deg. So i ordered a new Taco 014 to replace his and all is well. Thanks to those who responded.


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