# RIFENG MANIFOLD



## 91LMS (Dec 7, 2011)

has anyone used a rifeng manifold with their radiant heat?  i bought a 6 port manifold and seems that i overlooked that they say it only works with pex-al-pex.  this could be a problem where i have already pulled in just o2 barrier pex in my floor.  i dont know the differance between the two and if there would be a connection issue.  i have seen that the pex-al-pex will not work with sharkbite fittings where pex will.


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## 91LMS (Dec 7, 2011)

no one has had an issue or experience in the differance between standard o2 pex and pex-al-pex???


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## stee6043 (Dec 7, 2011)

I've never heard of the manifold you mention above.  I do, however, have experience with Pex-AL-Pex.  I can assure you that it is not compatible with standard pex fittings including sharkbites.  This type of pex has a layer of aluminum sheeting inside the tubing.  Hence the "-AL-".

  You could always convert from the -AL to standard pex (or copper, or black pipe) with a variety of fittings but I personally would not want to gum up my own system with such a conversion. Can you return your manifold?


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## 91LMS (Dec 7, 2011)

when ordering the manifold the connection fitting part numbers are selected depending on the type tubing that is used.  they are compatible with either types of tubing.


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## HeatFarmer (Dec 31, 2011)

I have 2 of these manifolds. They install very easy. You simply select a different connection to the manifold. I bought 1/2" pex fittings which fit the manifold on Ebay for 1/2 the price of anywhere else. Now if only they came with better instructions for balancing & purging.....


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## afblue (Jan 6, 2012)

They make both Pex and Pex AL Pex compression fittings for them. I have a 10 Port Riefing manifold with 5 Pex-Al-Pex, 3 barrier pex, and 2 more to be used as Barrier. I had to buy a set of Pex AL Pex  compression fittings for mine. The difference is the center "nipple" of the compression setup on Pex AL Pex has rubber O rings. barrier Pex is just metal ribs. The Pex AL Pex needs the rubber O rings because the compression collars cannot compress the Aluminum layer to seal reliably.

http://www.pexsupply.com/Rifeng-MA-50PAP-1-2-PEX-AL-PEX-to-EK20-Loop-Fitting-Assembly

http://www.pexsupply.com/Rifeng-MA-50P-1-2-PEX-to-EK20-Loop-Fitting-Assembly


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## 91LMS (Jan 6, 2012)

do you guys use the actuators for your zones or circ pumps?


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## afblue (Jan 6, 2012)

I used 2 wire actuators from Blue ridge company because I am using the manifold for multi zone applications. Are you using all the 6 ports together for one radiant system, or for individual zones that you want to control separate?


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## 91LMS (Jan 6, 2012)

3 zones off my 6 port manifold.  i am thinking the only way to do this is to use the actuators.  just didnt want to get locked into something that i had to mail order if i had one go bad.  maybe a spare on hand will be a good idea.


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## afblue (Jan 6, 2012)

I ended up finding out that a single Grundfos Alpha to circulate all the water in you zone loops, the actuators to control each pair of ports for the zones, and a Taco Zone Relay control is the optimal setup of components and controlability.


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## 91LMS (Jan 6, 2012)

thanks afblue, that was precisely my game plan for my radiant plumbing.  was going to turn towards a grunfoss variably circ to move the water from my wood boiler to my fossil boiler.


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## 91LMS (Jan 16, 2012)

finally got the manifold and pex all piped in.  plans to cut into the fossil boiler this week and make provisions for the wood boiler while i am drained down.  the instructions for the manifold are like brail but after second guessing myself for a couple days, it appears i have my supply and returns hooked up backwards.  my thoughts were that the flow gauges would be on the return side but i am mistaken?????  easy fix though, i think i can swap the manifold tubes top to bottom and all should be good.....


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## DaBackBurner (Jan 16, 2012)

Are you 'pushing' into the mixing valve? I believe you should be 'pulling' through the mixing valve to get proper mixing. Maybe I'm viewing this incorrectly and need another cup of coffee.


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## DaBackBurner (Jan 16, 2012)

Ok half a cup down and either I'm missing something or you should move your pump to the right side of the mixing valve between it and the manifold, to pull through the mixing valve. Otherwise improper, possibly no mixing, or improper flow through your loops will occur. Maybe it's just one of those days and I need to take a break from the computer and go split some wood though.


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## 91LMS (Jan 16, 2012)

you are making the correct observation i am in fact pushing through the mixing valve.  wouldnt it work either way though with return water having flow back out of the manifold?


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## DaBackBurner (Jan 16, 2012)

If you are pushing into a mixing valve you would need another pump to pull on the other side. Water will take the least resistive path...if your mixing valve is open all the way say, most of the water will want to bypass the manifold hence lower flow into your loops if it is closed most of the water will want to flow through the manifold and return without mixing. Your mixing valve will act more like a diverting valve the way you presently have it rather than a mixing valve thus creating varying flows into your loops rather than a mixing valve where flows in your loops will be fixed with varying temps. Hope that helps explain it.


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## 91LMS (Jan 16, 2012)

after thinking about it, i can see where i have gone wrong....  now to take half a days work, chuck it out the window and figure how to make it work....  if i put the pump, pushing towards the manifold, and find a place to put my mixing valve(basically where the pump is now), that should be the correct way?   its not the tubing i am worried about but the damn fittings might as well be made of gold!


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## DaBackBurner (Jan 16, 2012)

Yeah I know it is a PITA but you will be happier when it works correctly. I don't know for sure but it looks as though you have room to the right of your mixing valve to put your pump with flow into the manifold, I wouldn't change your pex lines around unless it would inhibit your design parameters of where the hottest water needed to go first...yes it will be horizontal but there are many pumps installed this way with no ill effects. Either put the pump on the supply side like that or put it between the 'T' and the manifold pumping away from the manifold (the return side) and your pump will experience lower water temps which is always a good thing too. Sorry to ruin your day, just would hate for you to have a system not work like you thought.


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## DaBackBurner (Jan 16, 2012)

I took a peek at the pixture again...you don't have the 'depth' between the copper and the pex to install the pump do you?


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## 91LMS (Jan 16, 2012)

the copper is actually about 4 inches off the wall.  so my plan is to put the pump where the tekmar valve is.  put a ball valve where i cut the top pump flang pipe off, extend that pipe to the tekmar valve further down where there is more room for the valve before the 90 behind where the pump will be relocated and the put a 90 on the pipe i have t'd off the return side of the manifold for my mix side of the valve.  wont look as odd but it will all fit and like you said will actually work correctly.  this will be the least intrusive labor and cost wise, wish i was smarter from the get go.  i really appreciate the heads up and help.


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## SmokeEater (Jan 17, 2012)

91LMS said:
			
		

> finally got the manifold and pex all piped in.  plans to cut into the fossil boiler this week and make provisions for the wood boiler while i am drained down.  the instructions for the manifold are like brail but after second guessing myself for a couple days, it appears i have my supply and returns hooked up backwards.  my thoughts were that the flow gauges would be on the return side but i am mistaken?????  easy fix though, i think i can swap the manifold tubes top to bottom and all should be good.....



In physics a push or a pull is a force.  I'd say it doesn't usually matter where the pump is in the circuit.  Looking at your mixing and manifold board what I would do is to put a spring check valve in your plumbing.  If the pump is on the hot side and pushing toward the supply manifold,  then a check valve should be placed so that it checks the possible reverse flow through the cold input to the Tekmar.  Put a second check valve(swing check) in the horizontal line between the supply manifold and the input T from the Tekmar.  Maybe it's too late at night and I can't understand the plumbing but that would be an easy fix.


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## RobC (Jan 17, 2012)

DaBackBurner said:
			
		

> Yeah I know it is a PITA but you will be happier when it works correctly. I don't know for sure but it looks as though you have room to the right of your mixing valve to put your pump with flow into the manifold, I wouldn't change your pex lines around unless it would inhibit your design parameters of where the hottest water needed to go first...yes it will be horizontal but there are many pumps installed this way with no ill effects. Either put the pump on the supply side like that or put it between the 'T' and the manifold pumping away from the manifold (the return side) and your pump will experience lower water temps which is always a good thing too. Sorry to ruin your day, just would hate for you to have a system not work like you thought.



Re: Position of pump. It's the position of the motor that is important. You want it on it's side just the way you have it now, regardless of whole units orientation. The motor shaft has to sit on the bearings so motor has to be parallel to floor.
If you can put it on the return side all the better too. If you do that you may need a check valve on the supply side.


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## 91LMS (Jan 17, 2012)

grunfoss says it doesnt matter which way the pump is installed.  i have taco pumps that have been mounted vertically for 20+ years with no failures in my baseboard system.  i does make sense to me now that if my pump were to be after the tekmar mixing valve that it could pull both hot input and the mix leg through the valve at the same time as opposed to my pump pushing hot supply water through the valve that would want to bypass the radiant loops and just return to the boiler via the cold port in the valve.  i plan to fix this tonight so i want to make sure its correct.


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## huffdawg (Jan 17, 2012)

it does matter  which way its installed. the pumps axle should stay horizontal.   The grundfoss comes with a piece of paper denoting pump orientation . there are three sketches  of which way it can be orientated 2 with check marks and 1 with an X.   the x has it with the pump shaft vertical
Go to this link and scroll down to page 22  

http://www.us.grundfos.com/web/download.nsf/Pages/DB9E15987978351F88256C4E006EA652/$File/L-UP-PG-001.pdf


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## 91LMS (Jan 17, 2012)

ahh, i see what you are saying now.  i would have only thought to mount the pump in that fashion anyways.  the pump motor will not change and the housing will be now mounted horizontally.  just will have to reindex the pump in the house after i get it mounted.


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## DaBackBurner (Jan 17, 2012)

SmokeEater said:
			
		

> 91LMS said:
> 
> 
> 
> ...



My pushing and pulling reference probably wasn't the best terminology as the force is a force. I should be saying flow. Check valves will work as well. I think most pro's if they had their preference and space limitations were not an issue etc. etc. would prefer to pump vertically up for better air removal.


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## 91LMS (Jan 17, 2012)

i did talk to a plumber/friend (where the hell was he this weekend, lol)  he did say that it should pull through the valve also and to put a swing check valve on the cold side of the valve.  so do i cut this thing apart, move the valve and put a swing check in the cold side to the mixing valve or do i just put a couple swing check valves in???


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## DaBackBurner (Jan 17, 2012)

As long as the checks don't create any undue head pressure I can't see why not to use them. If it were me I would cut it apart put the mixing assemply on the vertical portion of the piping, and put my pump on the return side pumping up (in your case the right vertical pipe) as long as I was pumping away from my pressure tank, which I have no idea where its located in your system. Thats just me though, if your plumbing friend is willing to come out and take a peak it can make all the difference in the world to have a pro 'see'. My comments were only in respect to the picture I saw...and I thought I saw something not quite right.

(Edit: And who knows, after a beer or two, he may see something else that doesn't look quite right.)


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## 91LMS (Jan 17, 2012)

the pressure tank is about 10-12 feet away at the boiler where the lh vertical pipe will t into my boiler.  i am assuming you are talking about the expansion tank???  i dont have a hot water pressure tank.  i was planning on just one swing check on the mix leg to the valve.  thanks a bunch for all that are giving advice or insight.  i greatly appreciate the help and glad that i posted my pic.  kick in the ding ding cuz i was pretty proud but more than happy to get this straightened out now.

my pump will be getting mixed water at about 140 deg so i didnt think it would bother on the hot side....


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## SmokeEater (Jan 17, 2012)

huffdawg said:
			
		

> it does matter  which way its installed. the pumps axle should stay horizontal.   The grundfoss comes with a piece of paper denoting pump orientation . there are three sketches  of which way it can be orientated 2 with check marks and 1 with an X.   the x has it with the pump shaft vertical
> Go to this link and scroll down to page 22
> 
> http://www.us.grundfos.com/web/download.nsf/Pages/DB9E15987978351F88256C4E006EA652/$File/L-UP-PG-001.pdf



Sorry to DaBackBurner and Huffdawg, My brain was "mixing" the word position up with location.  My apologies.  In 91LMS's solution, I do think that check valves in the right location will work.  Also, I agree,  the pump shaft should be mounted horizontally.


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## 91LMS (Jan 17, 2012)

even still with swing checks installed if i am pushing water at the valve and the manifold it wont mix properly right?  it would prevent flow from bypassing the manifold and returning to the boiler but would it actually "draw" the return water into the return side of the valve to mix with hot?  that still seems to be a problem without moving the valve given the higher resistance to flow with the radiant loops as apposed to the ease of bypassing via the 1" copper.


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## DaBackBurner (Jan 18, 2012)

Yeah that's what I'm thinking. You won't achieve proper mixing unless your distribution pump is on the right side of your mixing valve pumping into the supply manifold or the right of the 'T', between that and the return side of the manifold pumping away from the manifold, per your picture. But you said your expansion tank is on your supply side fairly close (the side with the pump) so I would pump away from the nearest point of pressure introduction, hence the supply side in your case. Flow from the supply can then mix with the return from your distribution manifold through the mixing valve, hence mixing. If your pump is flowing into the mixing valve I just don't see how it can mix properly with or without check valves, but maybe I'm mistaken. Maybe there is a pro or two that could interject.


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## huffdawg (Jan 18, 2012)

https://www.hearth.com/econtent/index.php/forums/viewthread/85987/

Heres I link  scroll to the bottom and therre is a pic. of my infloor circ and mixing valve.
the top is supply and the bottom is return

Huff


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## Willman (Jan 18, 2012)

Heres a pic of what your trying to do.
http://www.houseneeds.com/shop/heatingproducts/radiantheating/housepex_mixing_module_main.asp


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## 91LMS (Jan 18, 2012)

well, she's fixed!  i appreciate the insight from all of you, could have been really disappointed when i put the radiant to use had i not corrected this.  now to get it tied into the fossil boiler and get my wood boiler plumbed up and online!


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## DaBackBurner (Jan 18, 2012)

Nice! Looks like it was a 6-pack job to me.


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## huffdawg (Jan 18, 2012)

Now your cooking with gas. Looks good.    Would took me a least a case of American beer.    Must not be online right now ,valve is shut off.

Huff


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## 91LMS (Jan 18, 2012)

not online, gonna take the day off friday and drain my system down and get the radiant online.  all of a six pack job, plus the couple while cleaning up, then a couple to admire the corrections, and and and, lol.  i actually think it looks better now than my origanol design.  now just to drink heavy and hope for the best in getting all the air out.


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## Jwson1 (Feb 5, 2013)

Did the setup work well for you? I'm working on putting radiant heat on the first floor and was going to use your pic to do mine.


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## 91LMS (Feb 5, 2013)

works great, no issues

mine is actually 3 differant zones powered by the actuators.  if you dont have multiple zones it will be cheaper as you wont need the actuators and just keep the valves open manually.  i do wish that my actuators had end switches so that i could have wired to turn the pump on once open.


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## Morgan (Feb 5, 2013)

As confirmed by others, reposition the pump so it pulls through the 3way valve.  You can also buy an actuator for your Tekmar valve and hook it up to an outdoor air sensor, this would modulate the valve based on outdoor air temp.  I also like having thermometers installed on supply and return so I can keep an eye on what's happening, I think that is what I see at the supply and return valves, if not I would consider adding them.


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## 91LMS (Feb 6, 2013)

Morgan said:


> As confirmed by others, reposition the pump so it pulls through the 3way valve. You can also buy an actuator for your Tekmar valve and hook it up to an outdoor air sensor, this would modulate the valve based on outdoor air temp. I also like having thermometers installed on supply and return so I can keep an eye on what's happening, I think that is what I see at the supply and return valves, if not I would consider adding them.


 
pump does pull through the valve, thanks to the heads up of the folks on here prior to me filling the system with water.  didnt realize there was a actuator for the tekmar.  i will look into that for sure.  right now its modulated with beer in hand while i sit in a chair and monitor boiler and radiant temps...


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