Garn pump

[leon]

So what you have now is not at all what page 24 in the Garn manual recommends to have with a circulator with flooded suction in the front of the boiler pulling water of the bottom of the boiler sump and pushing this cooler water back to the top to be reheated in the second drawing on page 24????

the upper drawing on page 24 seems like the piping set up you should really have for your needs.

 

[Woodfarmer1]

I think you need to look at the picture again Leon, it draws the water off the top of the tank (red line) and returns at the bottom (blue line).
I have what is on page 28 of the 2013 manual which is only 47 pages.

 

[maple1]

I think my next step would be checking and verifying all the temps in & out of everything. Not sure I see temp sensor on the hx inlet. Is it under the black tape I see? Pipe sensors should be wrapped with insulation. Also I see a lot of up & down and zig zagging - no chance there's trapped air anywhere?

 

[Woodfarmer1]

Yes the sensors were all taped and insulated, I just put the new pump on Saturday, there was lots of water, no air. I will reinstall the insulation this week

Has anyone run a Garn with an open system in the house, just upping from the Garn through my rads and pex without the heat exchanger?

 

[maple1]

You really should check and verify all temps before planning more changes, IMO.

 

[TCaldwell]

It looks like the garn supply reduces in size at the union from black iron to copper, maybe it’s the difference between pipe types

 

[maple1]

Isn't black iron and galvanized sort of a no no on an open system? Don't know how much of an issue it might be though.

 

[Woodfarmer1]

It’s 1 1/2” black iron to 1” copper with the dielectric union coupler just as Garn recommends. There is no galvanized
The water seems to flow good.

 

[leon]

Yes the sensors were all taped and insulated, I just put the new pump on Saturday, there was lots of water, no air. I will reinstall the insulation this week

Has anyone run a Garn with an open system in the house, just upping from the Garn through my rads and pex without the heat exchanger?

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I believe a lot of them are piped like that to heat a home.
what you would have is no different than running an open system forest eater with circulators inside boiler shell. As long as you use boiler treatment and have the water PH checked annually. The exposed area open to air area is above the water line so it is no different than an open system forest eater.

 

[Woodfarmer1]

Ok Leon, that’s the best news I’ve heard yet.
I read about this somewhere, I just have to find it now

 

[TCaldwell]

As a test run the garn pump with the pressurized side pump off. See if the tank temp will equalize with the supply temp.

 

[Buzz Saw]

The new Garn's come with a filter kit that allows constant filtering/ mixing if the water.

Woodfarmer do you have the filter kit installed?

Sent from my SM-G950U using Tapatalk

 

[maple1]

Ok Leon, that’s the best news I’ve heard yet.
I read about this somewhere, I just have to find it now

Don't plunge into something else without verifying what your system is & isn't doing now, first.

Tom above mentioned a quick simple test to do, for one thing. Others have been suggested that have not been replied on.

You really need to have more (reliable) temp measuring at way more places than just the two gauges you are going by. My first thing to verify & measure would be - what is the temp of the water at the tank supply piping exit point & how does it compare to the tank guage you have been going by?

There could be all kinds of pitfalls with trying to run an open system, I don't think I would go there.

 

[Woodfarmer1]

Right now the Garn controller has tank 118, my cheap infrared heat gun has black pipe furthest from tank so,about 4’ at 114 and the last elbow before the pump is 109.

There is 72’ of thermopex type insulated buried down almost 5’ and the temp was only 0 Celsius or 32 Fred last night and the temp at the panel in the basement is at about 108.

It’s strange that at low temp there is only a 10* difference but when the boiler is at 190* I only get 166* or so in the basement secondary panel?

I doubt I will do any more to the system right now until I can get someone to figure out why there is so much heat loss once i button it back up with the insulation.

 

[leon]

Hello Maple1,

Due to the Garn open reservoir which is at atmospheric pressure plus the water weight difference he has an open system already that will require filtration, water testing and boiler treatment.

 

[leon]

The various brands of insulated buried Pex have a set temperature loss per foot or per one hundred foot of length.
I think its the logostor brand that has a heat loss of 1 degree per one hundred feet from what I remember.

 

[TCaldwell]

As above I recommend you run the garn side only, check temps, if they get close then run the load side and watch the temps. Does your pressurized pump run all the time or only during a call for heat, if only during a call , the temps will drop in the underground pipe and if intermittent enough ( like when your supply temps are the highest and your zones are calling infrequently) the underground pipe will take along time to heat up, espically if the flow is not enough., can you run a zone to run the pressurized pump for a few hrs to see if the temps get closer?

 

[TCaldwell]

Forget trying to chase this with a ir gun, spot checking with something as inaccurate. Get 2 azel dsp60’s probably 120$ at supply house. Each one has 2 sensors with a live display to watch as the process unfolds, place the sensors on each of the 4 flatplate connections.

 

[maple1]

Hello Maple1,

Due to the Garn open reservoir which is at atmospheric pressure plus the water weight difference he has an open system already that will require filtration, water testing and boiler treatment.

Yes. But do you (we?) know anything about the rest of his system - for example height relationships of everything? Also there are lots of warnings & precautions about doing it in the Garn manuals. 'Could be pitfalls.'

 

[surefire]

Tom, would you provide a link for those temp sensors? Thanks.

 

[TCaldwell]

Azel ds 60p is the correct numbers, just google it and there are several sellers

 

[Woodfarmer1]

TC,I unplugged my secondary when I fired the boiler. Boiler 170, ws and wr were both close to 155. Then when I got to a full burn I plugged my secondary back in and boiler 185 ws 174 wr 158 my temp at secondary is close at 155.

So the largest drop is from boiler temp to HX. There is 4’ of black 1 1/2” pipe and another 6’ of 1” copper before the pump and a foot or so of 1” copper to HX. As you can see from the above pictur there are plenty of 90* elbows.

 

[Woodfarmer1]

The new Garn's come with a filter kit that allows constant filtering/ mixing if the water.

Woodfarmer do you have the filter kit installed?

Sent from my SM-G950U using Tapatalk

No I just learned about that last week. I would like to know if any other Garn users experience this same problem. I think if the filter is required then it should be provided to us free of charge.

I had an empire elite 100 before the Garn and one of the main problems was rotting out caused by cooler water mixing. I had a fairly early version with no problems, however all owners were advised to install a danfos mixing valve or some crap.
It really ticks me off when these manufacturers have problems and expect the customer to pay to rectify the situation when we have already payed plenty for their boiler.

 

[maple1]

I would insulate that pipe. Well.

I don't think upping the boiler flow will do anything for you, I think if it was too slow you would see a bigger dt on the boiler side of the hx when the house side is running. But what is the house return temp at the hx? And are these temps accurate? And what is the temp at the boiler outlet?

 

[TCaldwell]

if the secondary or load side was unplugged, and you still have a 15 deg differential just running between the hx and back to the garn, I’d say it could be sensor placement or still a plugged hx. Is it possible to move the tank temp sensor to the the boiler metal surface right where the supply pipe leaves the garn, that’s where I have my supply sensor. Don’t put it on the actual supply pipe, as if the flow stops the temp will drop. Put some insulation over the three sensors and see if the temps get closer before you plug the load side back in. The garns that I service around me with the temp sensors in the tank never match up at the hx temp. The filter you are referring to is a bypass filter meant for a low flow of 1gpm To collect debris, sediment ect, there’s really no tank mixing going on with it.