So I just bought a house that has 2 separate plumbing systems, like totally separate. I want to connect them together to eliminate one of the hot water tanks. There are 2 recirc lines and I need to know how to hook up 2 recirc lines into 1 recirc pump?

Can someone maybe post a diagram or talk me through it. Thanks in advance.

KB

It is extremely difficult to give you an answer without knowing all the info like why are they separate in the first place you say they are totally different systems I’m unsure what that means is 1 part of the heating system or are they separate just because of the distance and amount of piping they serve … I would leave it be it’s probably the way it is for a reason

LEAVE IT BE

==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

yeah, the concept is pretty simple but the piping can range from a one to a ten.

you keep tank 1
you eliminate tank 2
you take the hot outlet from tank 2 and bring it back to the hout outlet of tank 1
you take the recirc line from tank 2 and bring it back to the recirc line of tank 1

so take this picture and pretend it is tank one.
the tank is on the left and the piping is on the right.
now flip the picture so the tank (#2) is on the right and the piping is on the left.
put the pictures side by side and simply put this is what you have.
so now the concept is that tank 2 goes away and the red pipes tie together and the green pipes tie together.
again, we aree talking anywhere from a 1 to a 10 in complexity.

Thank you all for your help...and Merry Christmas!

When I connect the 2nd recirc and 2nd hot water feed line to the other tanks.....What is the best method?

Like have the 2 lines connected to 1 line and then connect to the recirc line? Then the same for the hot water feed line...

What I am wondering is if I just "T" into the recirc line will it pull the water through there as well as the the first recirc line?

Thanks
Kyle



Edited 2 times.

Each recirc line should have a balancing valve and a check valve, then tee them together into the pump.

you can try putting a tee for the recirc lines.
something will pull but what pulls and how equal the flows are depends on total resistance of each loop.
the worst that will happen will be one will pull and one won't. in this case (as suggested) you will need to install a couple of valves and balance the flow. balance the flow by leaving open the valve that is not flowing and partially closing the valve that is flowing.
merry christmas to you..

I have only done one recirc system that had 1 heater with 2 return lines from separate apartments. I used Caleffi balancing valves like this...[www.caleffi.com] They show a piping diagram like what Packy is talking about - I think.

System has been working fine for about 5 years.

I ran the lines back to the heater, installed balancing valves on each line, tied lines together and fed into 1 pump, then connected to cold water feed line to heater.

Like I said I have only done one system this way. Packy, HJ, Bernabeu etc have more experience then me and may have a better way to do it.

It makes no sense whatsoever that there are two systems if either one has adequate capacity to serve the whole house. You really, really need to know these answers before you start:

1. Why did someone go to the time and expense of installing two separate plumbing systems?
2. Does the system you intend to keep have the capacity to serve the whole home?
3. If you do combine the two recirc systems, will all of the target bathrooms actually get hot water quickly? Several of the previous replies have discussed balancing, pipe sizing, etc.

It seems preliminary to offer you any advice about your complex new recirc system without understanding all the target bathrooms and their fixtures, the length of all the pipe runs, etc. With zero information, it's a good bet that neither of your heaters or recirc systems has adequate capacity to serve the whole house. If either one did have adequate capacity, why are there two systems?

(edited to fix error pointed out by bernabeu-thank you!)



Edited 2 times.

Quote

..... it's a good bet that neither of your heaters or recirc systems has inadequate[sic] capacity to serve the whole house. .....

ADEQUATE



each system INDIVIDUALLY is inadequate .... that would be WHY there are two systems

==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

geesh... you shut off one heater, run a couple of pex lines with valves where needed and tie them into the other heater.
if it turns out that this change will bring about the end of civilization as we know it then close thw new piping and turn on the old heater.
the owner wants to save some energy, save some money in the long run and do the work himself?

suffice to say that depending on the complexity of the existing piping the job can run anywhere from a one to a ten.

?????????????????? are you advocating installing/leaving dead ends ?????????????????????


WOW

==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

Thanks all for the help.

I am finding that many homes in TX are set up in a multiple separate plumbing system. Not sure on the reason just yet.

But yes need to find a way to get utility costs down....

Not to make this difficult but just seems like you should be able to attach the 2 recirc lines together into 1 recirc pump. Without getting into the science of fluid dynamics....

The balancing valves are good ideas to force more fluid from one system if one is hogging all the water!

Thanks again and hope everyone had a Merry Christmas!

the MAIN issue is: Why, when it is more expensive to install, are there two separate systems?

? are there ACTUALLY two separate systems or merely two tanks serving opposite sides of the home ?

perhaps, because of the 'total load', it was cheaper/easier/more cost effective to have two 'standard' residential tanks with 'split delivery' than one HUGE commercial grade 'tank' serving all


you really really really could use a PROFESSIONAL plumber on site or post an actual 'as built' sketch of what you have

==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638



Edited 1 times.

bern... it is getting more and more difficult to ignore your union based, nobody can do it better NEGATIVE comments..

have a nice day..

union ... non union ... makes no difference


dead ends in potable water piping are unhealthy and potentially dangerous AS WELL AS AGAINST CODE for the same reason(s)



stagnant water which can/may mix with one's drinking water is DANGEROUS (albeit, evidently, it takes union training to avoid)


dead ends in plumbing systems are N/F/G

==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

I wont be deadending anything. I am asking about extending... the problem is I need a mechanical/ commercial plumber to come out and consult. The few I have had out here are just residential and they dont know how to solve the problem properly.

Also to be precise the house has 3 separate systems. It is a big house that is spread out. But what I am trying to do is... on the same side of the house combine water heaters. They each have their own recircs. I want to just have one recirc and I am adding a tank to the upstairs system.



Edited 1 times.

you will need to install a 'manifold' on a single pump's suction side to combine return lines

each return going into said manifold will need a balancing 'cock valve' - said valves are DESIGNED for balancing

you want a 'small but steady' flow rate through each return

you want all return piping to be THOUROUGHLY insulated

HOWEVER

you will much better served with SEPARATE returns (centrally 'localized') even if you go to ONE tank



==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

don't ya love the hose valves located right above the electrical box on the circulator?

watertight boxes properly connected with 'sealtight' flex conduit


as per code

==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

the boxes are part of the circulator.

THEREFOR the boxes, as per CODE, are watertight


for example only:



note the watertight connector

==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

i suspect those are for use in a harsh, damp enviroment?
note the screws in the main body appear to be stainless.

my point is that a 3-4 dollar brass nipple to extend the hose valve out a few inches is certainly cheaper than a hundred or more for a waterproof circulator. BTW, i have never seen one like that.

'cheaper' price is seldom least cost over time

UNLESS

the cheaper item is actually the 'equivalent equal' of the specified item




properly installed piping to good or best practice (which most often EXCEEDS the minimum code) is, IMO, the most cost effective over time


? remember the old ad: pay me now, or pay me [much more] later ?

==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638