Move The Location of a Check Valve…Would It Be Better and Is It Worth The Work?

[Sid]

So it’s the second season on my system, and I’ve been doing some watching and thinking about improvements I can make. Overall it’s working great and I have no complaints, but I have noticed that I have some unwanted mixing that that I might be able to avoid with minimal re-piping.

A link to my thorough install post and system planning/build is here: https://www.hearth.com/talk/threads...iler-with-1000-gallon-thermal-storage.138501/

You can see in the current piping schematic that when C-1 has a greater flow than that of P-1, it will end up mixing hot water with the return water and flow through the tee directly below it back to the diverter valve and then to the bottom of storage. I feel in this scenario I’m wasting much of my precious hot water and resulting in sending ‘warmed’ water back to storage instead of the nice cold water actually coming back from my baseboards. To prevent this, currently I have the speed of P-1 set to high and C-1 to low and this has helped quite a bit. Now I’m realizing that I have mixing of cold return and hot from supply going back through the circuits. This is better than back to the bottom of storage but ideally, I’d like pure cold/return going back to bottom storage and pure hot/supply going out to circuits (unless return is hot enough to activate the 72C cartridge in the diverter valve, which would then send it back through supply).

A ‘simple’ re-pipe of the check valve might accomplish what I’m looking for as you can see in the Rev. 1 Drawing. (Below)

Going further, I see I might be able to do a similar thing for the fossil backup, which would allow me to remove P-1 completely and stop all mixing (instead of trying to match C-1 and P-1 flows which is really hard with 4 zones), even though I don’t care about the mixing when on oil or wood boilers are running, just when operating from storage.
Rev 2. (Below)

Also, P-1 is an Alpha 15-55 and I wonder if running this on speed 3 is bad for it when only one zone that is ½” pipe is all the flow it’s getting. I can definitely hear the pump and the water through pipes (too high of velocity) and I don’t know if I’m causing harm to the pump or piping (erosion).

So, would it be better? Am I missing something? Is it even worth it? Right now I start the boiler every night right around the same time (5:00-7:00 PM), fill it up before sleep, boiler is out before I wake up and the 1000 gal storage easily keeps the 3000+ sqft air leaky log home (working on sealing it better) warm until the next start.

 

[velvetfoot]

I'm not seeing why you need C-1. P-1 is an Alpha that changes pressure to adapt for when different zones open? Why do you need more than that? That seems like the latest and greatest. You have a boiler feed pump for each source.

I like the check valves too.

 

[Mike Fromme]

You can see in the current piping schematic that when C-1 has a greater flow than that of P-1, it will end up mixing hot water with the return water and flow through the tee directly below it back to the diverter valve and then to the bottom of storage. I feel in this scenario I’m wasting .

Are you sure about that?

With C-1 and P-1 pumping in series all the flow would be through the open ZV. The T after c-1 wouldn't split flow into two directions. Worst case is the flow rate is too high through the zone but since P-1 is an alpha it would slow down to compensate.

 

[Sid]

I'm not seeing why you need C-1. P-1 is an Alpha that changes pressure to adapt for when different zones open? Why do you need more than that? That seems like the latest and greatest. You have a boiler feed pump for each source.

I like the check valves too.

"I'm not seeing why you need C-1." - which drawing are you talking about?

 

[Sid]

Are you sure about that?

With C-1 and P-1 pumping in series all the flow would be through the open ZV. The T after c-1 wouldn't split flow into two directions. Worst case is the flow rate is too high through the zone but since P-1 is an alpha it would slow down to compensate.

"The T after c-1 wouldn't split flow into two directions. " - If C-1 is outputting more than P-1 then of course it will flow through the closely spaced tees, like the intended purpose when used for hydraulic separation of circuits...problem is I don't want that when running on storage. I can't ever get C-1 and P-1 to match GPM (both are alphas and display which is nice) because C-1 is 1 1/4" and practically no length of pipe. With the zone valves P-1 circuit/s can be as small as 1/2" and large as 2 3/4". I really want to take advantage of the auto-adapt feature, and the only way I see how to do that is put a check valve in.

 

[JohnDolz]

"The T after c-1 wouldn't split flow into two directions. " - If C-1 is outputting more than P-1 then of course it will flow through the closely spaced tees, like the intended purpose when used for hydraulic separation of circuits...problem is I don't want that when running on storage. I can't ever get C-1 and P-1 to match GPM (both are alphas and display which is nice) because C-1 is 1 1/4" and practically no length of pipe. With the zone valves P-1 circuit/s can be as small as 1/2" and large as 2 3/4". I really want to take advantage of the auto-adapt feature, and the only way I see how to do that is put a check valve in.

Sid - you and the others certainly know more than me but I think I am about to attack the same problem you are describing. I am going to do it by installing a "electric zone/check valve" in the bypass as you laid out in 1 of yur diagrams. It will only open when my propane boiler fires (manufacturer states I need it to guarantee the proper amount of flow through the boiler). Unfortunately I installed 5 Alpha's in my zones + 1 Alpha that pulls water through my mixing valve (I use a mixing valve controlled by Outdoor reset to leverage low flow temps), if I had to do it again i would use zone valves as you have them. Once I have the valve in place I plan to set the Alpha in front of my mixing valve on Auto or as set pressure - my goal will be to have the GPM of that pump match the zone GPM usage. I realize the GPM reading on the Alpha is not accurate but my hope is that they are consistent so that if 4 zones are running at 1 GPM and my "main" pump is running at 4 GPM, I should be good. By the way I am in Burlington, CT you are most welcome to come take a look any time.

 

[JohnDolz]

I'm not seeing why you need C-1. P-1 is an Alpha that changes pressure to adapt for when different zones open? Why do you need more than that? That seems like the latest and greatest. You have a boiler feed pump for each source.

I like the check valves too.

That is exactly what my Swedish friend always says when he sees how many circuators I have.

 

[Mike Fromme]

C-1 is needed because of the diverting valve... Sounds like it's oversized though.

If you put a check valve between the T's wouldn't it open when P-1 is running? Then you be left with same situation you already have.

 

[JohnDolz]

C-1 is needed because of the diverting valve... Sounds like it's oversized though.

As I mentioned I am no expert but always trying to learn. I understand the C-!, I have a similar pump pulling through a shunt (mixing valve), which I assume creates a situation pretty much the same as the Diverting Valve. My question then is why is P-1 required?

 

[Mike Fromme]

I would think without P1 everything would work fine...for one loop around the zone... Then the check valve would open and there would be no more or very little flow through the zones... Then the check valve would close...and some more flow would go through the zones...

Basically just the amount required to hold the check valve open would flow through the zones?

ETA: talking about revision 2... Last schematic in OP

 

[Sid]

Sid - you and the others certainly know more than me

Lol, I actually teach IT...I've never even sweat a pipe before this...I have done my fair share of reading though and my wife has come to accept her husband obsesses about heating the house. Seems like you got a nice system going with the outdoor reset etc.

I like to grab a beverage and watch my system in the little free time I might get (two kids under 2) and I touch pipes, play with buttons on alphas and just thought of moving a check valve...the gain would be longer run times on storage which maybe I care too much about...starting a fire in this thing is easy and plan to do it every evening in the coldest part of the winter anyways. It sucks to look back and want to change things...many variables and hard to plan for everyone. I just wonder why anyone would ever draw a schematic with closely spaced tees (usually done for hydraulic separation) for heating from storage. The original drawing was looked at and given a green light by people who definitely know (or should know) more about these systems than you and I together.

 

[Sid]

C-1 is needed because of the diverting valve... Sounds like it's oversized though.

Even without diverting valve I think it would be needed?? The problem is its both oversize and undersized depending on P-1 right now. Purposely keeping undersized has indeed extended my storage...but equal would be the best and extend the most. (that's why I think just one pump in rev. 2 might be best.)

 

[JohnDolz]

I would think without P1 everything would work fine...for one loop around the zone... Then the check valve would open and there would be no more or very little flow through the zones... Then the check valve would close...and some more flow would go through the zones...

Basically just the amount required to hold the check valve open would flow through the zones?

Thanks, not quite sure which check valve you are referring to but no worries, I am confused enough with my own system. My "C-1" is an Alpha so my thinking is that once I put the valve in my bypass I can run that Alpha on a pressure setting so that as additional zones call for heat it will accommodate by increasing the GPM (same in reverse as zone turn off). I was thinking of replacing my Zone Circulators with Zone valves and running just off of 1 Alpha (see my post titled Replacing Calculaors with Zone Valves - damn auto correct but thinking about the various types of emitters I have I think I decided that it would be asking for trouble. Plus I just bought the Alphas.

 

[Sid]

I would think without P1 everything would work fine

In which drawing/scenario? Currently the way it is now I'd need it? Maybe I'm missing something?

 

[Mike Fromme]

In which drawing/scenario? Currently the way it is now I'd need it? Maybe I'm missing something?

I was talking about the last drawing... Revision 2.

Without p1 you'd be relying on the check valves to make the C circulators push water through the zone. But what happens if the check valve opens?

 

[JohnDolz]

Lol, I actually teach IT...I've never even sweat a pipe before this...I have done my fair share of reading though and my wife has come to accept her husband obsesses about heating the house. Seems like you got a nice system going with the outdoor reset etc.

I like to grab a beverage and watch my system in the little free time I might get (two kids under 2) and I touch pipes, play with buttons on alphas and just thought of moving a check valve...the gain would be longer run times on storage which maybe I care too much about...starting a fire in this thing is easy and plan to do it every evening in the coldest part of the winter anyways. It sucks to look back and want to change things...many variables and hard to plan for everyone. I just wonder why anyone would ever draw a schematic with closely spaced tees (usually done for hydraulic separation) for heating from storage. The original drawing was looked at and given a green light by people who definitely know (or should know) more about these systems than you and I together.

I sell IT and I know less about that than I do about heating. Have your wife talk to mine, she will get a whole new definition of obsessed. When I 1st installed my system both my plumber and the person that sold/installed my wood system told me that an Outdoor Reset would never work. Long story but I ended up working directly with the manufacturer in Sweden (even had him come to my house) and redesigned parts of my system to leverage what they call a shunt valve. This mixes water, controlled by my boiler, to hit a target temperature based on outdoor and indoor temps - the theory is that it gives me 20-30% better "mileage" out of my storage. My house is 72 degrees right now and I would bet if I went downstairs that I would see that I am running flow temp that is under 125 degrees. In case that wasn't enough just finished adding a 2nd shunt valve that is used to heat my DHW. By the way my system is so easy to start & load, I would say less that 10 minutes from start to finish, that my wife always heats with wood while I travel for work. We heat 100% with wood.

I have 9 year old twin boys, one helped me cut and unload a trailer full of 24-36" logs today, they run the wood splitter, split kindling - sit tight you have help on the way!

 

[Sid]

sit tight you have help on the way!

LOL, sounds good. My two year old uses her potty stool to load the boiler with kindling...now we just have to get her to start using the potty for it's intended purpose.

 

[JohnDolz]

LOL, sounds good. My two year old uses her potty stool to load the boiler with kindling...now we just have to get her to start using the potty for it's intended purpose.

Be patient, they will know everything before you know it.

 

[Dutchie84]

I am no expert but could you not get rid of the loop and make a supply and return header. And then get rid of P1 and just run both c1 and c5(assuming its an alpha or maybe you can replace it with p1) on pressure mode.

 

[Sid]

I am no expert but could you not get rid of the loop and make a supply and return header. And then get rid of P1 and just run both c1 and c5(assuming its an alpha or maybe you can replace it with p1) on pressure mode.

Very interesting and I like it...I'm surprised I didn't think of that before. It would have made my original piping easier also. I'll be sending your version around and see what other think as well, but seems to me the best idea so far.

 

[JohnDolz]

Very interesting and I like it...I'm surprised I didn't think of that before. It would have made my original piping easier also. I'll be sending your version around and see what other think as well, but seems to me the best idea so far.

Not suggesting this is the case with your system but I was considering doing something similar with mine and learned that I could/should not. My "Fossil Fuel" boiler is a Low Mass High Efficiency Modulating Condensing boiler. Since I also have that boiler running on an Outdoor reset I thought I could get rid of the Bypass (which is what I will essentially do with an electric zone valve when heating from storage), leverage low flow temps and eliminate the short cycling caused by the low Delta between Supply and Return. I called the manufacturer to confirm I could do this and they highly recommended against it. One reason for the bypass is to help "prewarm" the water going into the boiler (not an issue with low flow temps). The other reason was to make sure the boiler was getting the required GPM's - this one convinced me to leave the bypass open when the propane boiler fires (I rarely use propane so the risk outweighed the reward for me). I am not sure if the Boderus has a similar GPM requirement.

 

[Bob Rohr]

I like a two pipe tank connection. Here is the key to a two pipe tank connection. The header into the tank needs to be generously sized to eliminate pressure drop and unwanted flows.