Geothermal heat pump install with crawlspace encapsulation

[bb770]

Check the install instructions,usually want the unit set on a solid piece of foam. The way it is now , with block on the corners it's acting like an amplifier.Also, as buckeyefarmer stated, make sure they removed all the shipping brackets and bolts.

 

[doxford jim]

Hi guys,

Thought I would add this post to the all ready long list of contributors.

Earlier in the post I commented on how one of the two circulating pumps was considerable hotter (to the touch) than the other on my system and didn't really understand why.

Well, now I know why - the warm pump was starting to fail (slowly seized up). My system shut down on low pressure and I thought that was the compressor gas safety. Well I was wrong, the low pressure shut down was for the circulating fluid in the horizontal loops. The pump that failed was the first one that starts when the system kicks in - the second one starts when auxiliary heat is called for. This is as I understand it - didn't know this before and am on a learning curve right now !

After talking with the repair tech for the company that installed my WaterFurnace unit, it was suggested I swapped the roles of the pumps around - that is the second called pump be made the first called pump. This would enable the system at least to work. I didn't want to mess with the control board as I don't understand or follow electrical diagrams too well, so I swapped the wiring to the pumps. This way the second pump would start when the system started up and the other pump that failed was left disconnected.

Well, I tried it and it worked. The system is working for moderately cold temperature and I am guessing here, probably ok to around zero degrees 0F. I have a propane furnace that I can run at the same time as the geothermal unit to enhance temperatures if need be.

During this process I did some digging and found out a bit on replacing circulating pumps and flow centres - of which I knew nothing about before. Check link below:

http://www.waterfurnace.com/literature/geolink/im1547ew.pdf

I posted it as it makes things a bit clearer on what is involved. It also describes the function of the flow centre and how it is used. Might be handy for someone who didn't know about them (like me ).

I have a couple of questions that someone might be able to answer.

After replacing a pump the recommendation is to use the illustrated circulating rig for two hours to get air out of the system. If the pump is shut off with the three way valve when installation is done, and then carefully cracked open to allow residual pressure (exerted from the loop expansion tank) to bleed any air out of the pump, would this work ? If it can be done it would allow the owner to replace his own circulating pumps if done carefully. I think the two hour minimum time for using the separation unit would be expensive (travel time to and from residence plus at least two hours on site, probably three hours) at $100 an hour.

I priced out replacement pumps and they are around $350 each as far as I can tell. I need to replace the two and not just one pump as it's mate is going to fail as well eventually. The ones in the system are well over ten years old - maybe even 15 years. so replacing just one pump would be unwise.

Just thought I would share this information as it is handy to know.

I was surprise that the HVAC tech tried to tell me that I would need a new flow centre for around $1600 plus the cost of the pumps ! Replacement pumps is all I need at present IMHO.

Would appreciate comments from those that are familiar with the geothermal systems (I have horizontal ground loops) and what would you do in my case?

Thanks

 

[Country Geek]

Earlier in this thread I had complained about the noise that the system makes in my bedroom. Today the installer came out and looked at it and we found the problem. It was the desuperator pump. Turns out the line that it pumps into was resting on some of the PVC lines that drain fixtures in the master bedroom, and the vibration of the desuperator pump was being transmitted directly into the master bedroom via the tub! Installer solved it by physically separating the desuperator lines from the PVC drain lines and now the thing is as quiet as can be.

I was sure, because of the pitch and pattern of the noise, it was the compressor but it wasn't. Another clue is that while the noise was loud in the master suite, you couldn't hear it from inside the crawlspace where all the components actually are! That got him looking for referred vibration and he found it.

 

[techman]

Hi guys,



After replacing a pump the recommendation is to use the illustrated circulating rig for two hours to get air out of the system. If the pump is shut off with the three way valve when installation is done, and then carefully cracked open to allow residual pressure (exerted from the loop expansion tank) to bleed any air out of the pump, would this work ? If it can be done it would allow the owner to replace his own circulating pumps if done carefully. I think the two hour minimum time for using the separation unit would be expensive (travel time to and from residence plus at least two hours on site, probably three hours) at $100 an hour.

I priced out replacement pumps and they are around $350 each as far as I can tell. I need to replace the two and not just one pump as it's mate is going to fail as well eventually. The ones in the system are well over ten years old - maybe even 15 years. so replacing just one pump would be unwise.

Just thought I would share this information as it is handy to know.

I was surprise that the HVAC tech tried to tell me that I would need a new flow centre for around $1600 plus the cost of the pumps ! Replacement pumps is all I need at present IMHO.

Would appreciate comments from those that are familiar with the geothermal systems (I have horizontal ground loops) and what would you do in my case?

Thanks

If you close the 3 way valves to isolate the loops from the pump, you can then remove them and you should have minimal water loss. Take the new pump and fill the wet part of the pump with water, and replace it on the manifold. You can usually do this with a bare minimum of air getting into the system. I have replaced 5 or 6 pumps this way over the years and not flushed the system, and have had no problem. You are generally talking 30 or more gallons of water in the loop, and a teaspoon of air will slowly dissolve into the water. You may possibly need the pin fittings to add some water into the loop to increase pressure, if needed. They can be had for a few bucks online.

Just make sure that the valves are blocked (I usually set them to be open to the flow center and block the loops). Just remember to set them back when you are done.

paul

 

[cre10]

Hi guys,

Thought I would add this post to the all ready long list of contributors.

Earlier in the post I commented on how one of the two circulating pumps was considerable hotter (to the touch) than the other on my system and didn't really understand why.

Well, now I know why - the warm pump was starting to fail (slowly seized up). My system shut down on low pressure and I thought that was the compressor gas safety. Well I was wrong, the low pressure shut down was for the circulating fluid in the horizontal loops. The pump that failed was the first one that starts when the system kicks in - the second one starts when auxiliary heat is called for. This is as I understand it - didn't know this before and am on a learning curve right now !

After talking with the repair tech for the company that installed my WaterFurnace unit, it was suggested I swapped the roles of the pumps around - that is the second called pump be made the first called pump. This would enable the system at least to work. I didn't want to mess with the control board as I don't understand or follow electrical diagrams too well, so I swapped the wiring to the pumps. This way the second pump would start when the system started up and the other pump that failed was left disconnected.

Well, I tried it and it worked. The system is working for moderately cold temperature and I am guessing here, probably ok to around zero degrees 0F. I have a propane furnace that I can run at the same time as the geothermal unit to enhance temperatures if need be.

During this process I did some digging and found out a bit on replacing circulating pumps and flow centres - of which I knew nothing about before. Check link below:

http://www.waterfurnace.com/literature/geolink/im1547ew.pdf

I posted it as it makes things a bit clearer on what is involved. It also describes the function of the flow centre and how it is used. Might be handy for someone who didn't know about them (like me ).

I have a couple of questions that someone might be able to answer.

After replacing a pump the recommendation is to use the illustrated circulating rig for two hours to get air out of the system. If the pump is shut off with the three way valve when installation is done, and then carefully cracked open to allow residual pressure (exerted from the loop expansion tank) to bleed any air out of the pump, would this work ? If it can be done it would allow the owner to replace his own circulating pumps if done carefully. I think the two hour minimum time for using the separation unit would be expensive (travel time to and from residence plus at least two hours on site, probably three hours) at $100 an hour.

I priced out replacement pumps and they are around $350 each as far as I can tell. I need to replace the two and not just one pump as it's mate is going to fail as well eventually. The ones in the system are well over ten years old - maybe even 15 years. so replacing just one pump would be unwise.

Just thought I would share this information as it is handy to know.

I was surprise that the HVAC tech tried to tell me that I would need a new flow centre for around $1600 plus the cost of the pumps ! Replacement pumps is all I need at present IMHO.

Would appreciate comments from those that are familiar with the geothermal systems (I have horizontal ground loops) and what would you do in my case?

Thanks

What size heat pump? You looking at 2699's or 116's? It's kind of hit and miss not repurging. If you have too much air those pumps will cavitate and ruin them.

 

[Redneck in training]

Hi guys,

Thought I would add this post to the all ready long list of contributors.

Earlier in the post I commented on how one of the two circulating pumps was considerable hotter (to the touch) than the other on my system and didn't really understand why.

Well, now I know why - the warm pump was starting to fail (slowly seized up). My system shut down on low pressure and I thought that was the compressor gas safety. Well I was wrong, the low pressure shut down was for the circulating fluid in the horizontal loops. The pump that failed was the first one that starts when the system kicks in - the second one starts when auxiliary heat is called for. This is as I understand it - didn't know this before and am on a learning curve right now !

After talking with the repair tech for the company that installed my WaterFurnace unit, it was suggested I swapped the roles of the pumps around - that is the second called pump be made the first called pump. This would enable the system at least to work. I didn't want to mess with the control board as I don't understand or follow electrical diagrams too well, so I swapped the wiring to the pumps. This way the second pump would start when the system started up and the other pump that failed was left disconnected.

Well, I tried it and it worked. The system is working for moderately cold temperature and I am guessing here, probably ok to around zero degrees 0F. I have a propane furnace that I can run at the same time as the geothermal unit to enhance temperatures if need be.

During this process I did some digging and found out a bit on replacing circulating pumps and flow centres - of which I knew nothing about before. Check link below:

http://www.waterfurnace.com/literature/geolink/im1547ew.pdf

I posted it as it makes things a bit clearer on what is involved. It also describes the function of the flow centre and how it is used. Might be handy for someone who didn't know about them (like me ).

I have a couple of questions that someone might be able to answer.

After replacing a pump the recommendation is to use the illustrated circulating rig for two hours to get air out of the system. If the pump is shut off with the three way valve when installation is done, and then carefully cracked open to allow residual pressure (exerted from the loop expansion tank) to bleed any air out of the pump, would this work ? If it can be done it would allow the owner to replace his own circulating pumps if done carefully. I think the two hour minimum time for using the separation unit would be expensive (travel time to and from residence plus at least two hours on site, probably three hours) at $100 an hour.

I priced out replacement pumps and they are around $350 each as far as I can tell. I need to replace the two and not just one pump as it's mate is going to fail as well eventually. The ones in the system are well over ten years old - maybe even 15 years. so replacing just one pump would be unwise.

Just thought I would share this information as it is handy to know.

I was surprise that the HVAC tech tried to tell me that I would need a new flow centre for around $1600 plus the cost of the pumps ! Replacement pumps is all I need at present IMHO.

Would appreciate comments from those that are familiar with the geothermal systems (I have horizontal ground loops) and what would you do in my case?

Thanks

When my system was new I heard once a while air going through the pumps. There was also slow drip on one of the soldered connections. Therefore I released the pressure, fixed the leak and while it was depressurized I put a T in the outside loop pump inlet pipe and installed about two feet of 1" stand pipe with a manometer and bleed valve on the top. After that I periodically checked for presence of air by cracking the bleed valve. It took about two weeks to gradually bleed all the air out.

 

[cre10]

Pressurized systems are so 1980's and 90's. Besides some very low percentage installation applications I don't see why anyone would go with a pressurized system.

 

[doxford jim]

techman,

Thanks for your comments - I feel a little bit more confident now about what I have in mind. Since my system is still working with the one pump I am not in a critical situation yet - plus I still have the propane system as a back up. I am bothered by the comments the repair tech made regarding a new "flow centre" without saying why. When I said I only wanted to replace faulty pumps, the flow centre suggestion was dropped. This makes me think that the repair tech was just trying to make a sell without any basis for replacement. I should also get a couple of replacement capacitors methinks, as one failing would make the pump hard to start and run hot causing eventual problems.
I will PM you if that is ok, to get info on the fittings you mention.
Where the flushing plugs screw into the flow center, there is some blue coloured satins which I assume, is caused by the antifreeze liquid. Would that colour be indicative of the type of antifreeze used ? Where I live the winter temperatures can drop to -40C/-40F, so I doubt very much that water alone is used. It would be an antifreeze mix for sure. That brings up testing for pH and freeze temps - a couple of cup fulls would most likely be needed for this - no ?

cre10

"Pressurized systems are so 1980's and 90's. Besides some very low percentage installation applications I don't see why anyone would go with a pressurized system."

I don't have any choice - the system is already installed ( was done about 16 years ago or more). I am a 70 pensioner that has to budget on a low fixed income. I am trying to repair and maintain a heating system as economically as possible, without the outrageous prices that some people are apt to charge - just because they can.

Redneck in training,

Thanks for your comments. I too had thought of something similar where air bleed off could be done. To do that I would have to Tee into the loop lines at a high spot in the basement to gain the advantage. Will need to think on that one.

Thanks everyone, for your comments - much appreciated.

Cheers

jim

 

[cre10]

To me I would go with a new flow center to get a 5 year or more warranty on it. If you buy pumps separate it may only be a 1 or 2 year warranty. 2 pumps = $500. New flow center = $800.