Hydronic manifold problems

Harley_Dave

I just got my boiler up and running this past week. I have an air handler to take car of the main house and I have Pel-Al-Pex installed in the garage. I have 5 zones in the concrete and one zone is for a hanging heater in my shop.

When I went to start up the heat for the garage I noticed I had what seemed like very little if any flow on my meters. I closed off the main isolation valves for the manifold and hooked up a garden hose to try and flush the lines. The first line I got maybe 1-2 gallons of dirty water and then it stopped flowing. I moved on to do the other 5 lines and got no water at all.

I contacted Pex Universe where I purchased this manifold back in 2011 and she pulled up my order and told me it is a Rifeng SSM106 and they no longer make replacement flow meters for that model. I am guessing I need to install a new up to date manifold. The site glasses are glued in so I can't remove them to see it the plunger is stuck and I am hesitant on unscrewing them and the metal fitting.

The pex lines have never been flushed in 12 years so can I assume I need to try and push fresh water through these lines until they run clear?
Any and all advice is greatly appreciated,

Thanks,
Dave

hot_rod

It would be rare for all 6 meters not to read at all The plastic gets cloudy but the meter itself rarely plugs
You have iso valves, maybe remove one to see if the plunger is stuck

Harley_Dave

hot_rod said:

It would be rare for all 6 meters not to read at all The plastic gets cloudy but the meter itself rarely plugs
You have iso valves, maybe remove one to see if the plunger is stuck

I assume you are talking about the white valves on the top of my manifold?

hot_rod

Here is what is inside those flow indicators 
a plastic rod that moves up and down as flow changes, not much can fail

in the Caleffi version, the white cap is a wrench and you can turn the clear plastic meter to manually balance various loops, or adjust flow for varying heat output

You might soak them in CLR to clear them up a bit

Harley_Dave

hot_rod said:

Here is what is inside those flow indicators 
a plastic rod that moves up and down as flow changes, not much can fail

in the Caleffi version, the white cap is a wrench and you can turn the clear plastic meter to manually balance various loops, or adjust flow for varying heat output

You might soak them in CLR to clear them up a bit

I appreciate the information. Here are pictures of my individual Isolation valves. I assume once I remove the white cap the bottom white plastic part will also unscrew. I guess it can't hurt to pull everything out and soak them in CLR since nothing is working as of now. Any other advice you might have?

EdTheHeaterMan

Harley_Dave

Ed,

The manifold did come with a wrench for the flow meters. When I was working on closing them all and one of them felt like the threads may be messed up so I left it where is was. all the others threaded in and out fine. I will make an attempt tomorrow morning to get everything out and soaked. Then to get the pex lines flushed out.

Big Ed_4

The actuator plungers may be stuck ? penetration oil works....

hot_rod

The upper white plastic knobs are also used as shutoff valves. If you completely remove them the valve is wide open, do that when you purge.
If you tighten them down “clockwise” you essentially shut off all flow to that loop.
Is it possible you have them all cranked down. That would explain why the flowmeters are not showing any movement

And the red and blue manifold valves need to be open, handle parallel with the pipe.

Harley_Dave

Since I had little to no flow to the floor I decided I needed to flush the lines. I shut off the red and blue isolation valves and hooked up a garden hose to top row on the manifold and a drain hose on the bottom row. I closed all white valves and flow meters and open just one white valve and the corresponding flow meter. On the first one I did I got 1 maybe 2 gallons of dirty water and it stopped flowing. I went on and tried the other 5 lines the same way and got nothing.

hot_rod

Im not sure  you can flow backwards, try feeding into the red  manifold, purge from blue

The hose pressure may be pushing the valves closed

or maybe it pushed the disc off the valves. I have seen that happen when you flow backwards through a hose bib with high flow/pressure 

Harley_Dave

You may be correct on it pushing the valves closed. I plan on going downstairs shortly and I will try as you suggested and see what happens.

hot_rod

Some of the valve discs just snap onto a pin. Worse case you have to remove them all and reassemble the seal onto the stems

Harley_Dave

Bob,

You were correct. I switched my hoses and pushed water through the flow meter side and let it exit out the return side. I left all the flow meters open and closed all the return valves on top of the manifold and open one at a time, flushed and closed and repeated all 6 lines. It flowed fine and got some nasty looking water coming out. I have not yet tried running my heat through it yet but I will shortly. Just not feeling 100% today. I'll let you now how I make out.

Dave

Harley_Dave

Well I still have no flow at the manifold. I think I have narrowed it down to possible cause. My system has a Caleffi 521509A mixing valve on my feed and return and I also have a Watts LF7R dual check back flow preventer on the feed side. What is your opinion on one or both of these being clogged? The backflow preventer I can isolate easily to check it. With the mixing valve I'd have to drain the lines which run up to my air handler.

hot_rod

Really no need for that backflow device. It looks like a basic double check type BFD, which is somewhat restrictive.
Are the arrows on the pump pointing down, same with the backflow, pointing toward the manifold.

I'd open the union nut on the backflow and pull the guts out.

Turn the knob open and closed on the mix valve to dislodge any crud.

You are sure the pump is spinning? At least 10- 12 psi on your gauge?

is there a boiler up above this assembly? All the valves open?

Harley_Dave

The arrows on the pump are pointed down, I triple check that!! I can see the shaft on the pump spinning. The pressure/temp gauge you see on my inlet side is not working or not reading so I don't even look at it. My boiler is in a shed on the same level as the garage and I getting plenty of flow to my air handler upstairs.

Now if I open the bleeder on the return side of the manifold I do get lots of hot water flowing out the bleed outlet. That is why I think there is a restriction either in the mixing valve or the backflow preventer.

hot_rod

what do the temperature gauges read?
The red supply should read higher than the blue return to indicate heat us moving into the loops

If this is a slab it could take a day to warm

How long  are those loops? That is not much if a circulator for radiant systems

Harley_Dave

The arrows on the pump are pointed down, I triple check that!! I can see the shaft on the pump spinning. The pressure/temp gauge you see on my inlet side is not working or not reading so I don't even look at it. My boiler is in a shed on the same level as the garage and I getting plenty of flow to my air handler upstairs.

Now if I open the bleeder on the return side of the manifold I do get lots of hot water flowing. That is why I think there is a restriction either in the mixing valve or the backflow preventer.

The pump you see is only for the garage floor. There is main pump on the back of the boiler. There are 5 loops in the floor with a total of about 1100' of 1/2" Pex-al-pex. Runs are around 220 - 250'.

Harley_Dave

I pulled the backflow preventer out and other then a little dirty inside it seemed to work as intended. Bob, as you mentioned really no need to a backflow device so I will be eliminating that.

As far as the mixing valve goes it seems like I may need a new one. When I open and close the mixing valve it just feels like there is grit inside. I ran it in and out a dozen time and smack on it and still feels like there is some grit in there. I get very hot water coming into the mixing valve and it seems to go past the feed line to my manifold and over to the return and the feed to the manifold will get slightly warm and I think that is only getting warm from thermal transfer.

At least I have heat in the house and will just have to wait for the big brown truck to bring me a new mixing valve.

Big Ed_4

As mentioned pull out that back flow , a check is not needed either...

GroundUp

Have you also purged the pump loop? This is a pretty common occurrence with radiant and mixing valves. The odds of a stuck mixing valve are very slim, but the odds of an airlock are very high. Perhaps hook up your hoses again and purge the entire system, rather than just the floor loops.

Harley_Dave

I believe I had had that loop purged good but there is always the possibility I still have an air lock. I know that when turning the mixing valve it just feels like there is either grit in there or the valve itself is messed up inside. The new valve is supposed to be here tomorrow. I do have a fill/purge connection at my air handler that is the highest point on my system. I plan to fill from there and leave the line open that the manifold to make sure I have it purged good. I do appreciate everyone's help and advice!!

Harley_Dave

I do now have hot water flow after changing out the mixing valve and flushing the lines. However my flow seems really low. I believe Bob is right that the B&G pump is to small.

Right now I have a B&G #106197
1/12HP
RPM-1725
Max flow-33
Max head -8

I have a Grundfos UPS15-58 that I am going to try.
UPS 15-58-FC
1/25HP
RPM 2450
Max flow-17.2
Max head --19.4

Harley_Dave

I wanted to thank you all for your help with my problem. Since installing the new mixing valve and changing the pump from the B&G to the Grundfos I now have some decent flow through my floor. The B&G pump was not flowing very well and only had about 22psi. The Grundfos UPS15-58 is making 30-32psi, Again thank you all for your help.

GroundUp

I think your gauge is broken, because a 15-58FC is only capable of making 8.4 psi. Either way, glad to see you got it going.

hot_rod

I see you have a gauge just downstream from the circ.  A gauge at the discharge of the circ that is pumping away from the expansion tank would show the pressure differential added to the static fill.
Your pressure relief is on the suction side, so it will see a lower pressure. Otherwise it should be discharging at 32 psi. If it is a 30 psi valve?

this graphic shows the pressure relationships in a pumping away circuit

It looks like a pressure/ temperature gauge? Those are not always super accurate

pedmec

you said the pump shaft on the b&g was spinning but did you confirm the spring coupler was not broke.

Harley_Dave

GroundUp said:

I think your gauge is broken, because a 15-58FC is only capable of making 8.4 psi. Either way, glad to see you got it going.

This pump is only for the garage. I have a Grundfos UPS26-99 as the main pump at the boiler. I'm not sure how much having both on effects the pressure. The gauge is a cheap temp/pressure gauge and I needed something cheap to replace the one that was broke without spending a lot of money.

Harley_Dave

Bob, You're right that is a cheap temp/pressure gauge. I spent some money doing some repairs on my burner this year so I had to go a little cheaper on replacing the gauge that was in there previous. I'm not sure what happened to the old Caleffi 521509a valve but it would not let hot water flow into the garage. Replacing that valve was the ticket. I now have nice hot water flow. Loops are showing about .5-.6gpm and the floor is warming up nicely..

Harley_Dave

pedmec said:

you said the pump shaft on the b&g was spinning but did you confirm the spring coupler was not broke.

I actually pulled the pump out of the volute to confirm the impeller was spinning and it was.