learning and paying the price

don123

Hi Heating Help!
I have recently bought Dan Holohans books. Primary Secondary pumping, Pumping Away, Hydronic radiant heating. My Existing system has both high temp and low temp zoning.
over the years it worked. the near boiler piping is where it went down hill over the years.
I know now the the low temp return caused sludge, rust, blockages with circulators, mixing valves. copper piping, valves getting pinholes you name I had it. Now I am removing all of the piping, radiant manifolds, boiler everything but the onyx tubing. thankfully the tubing is in fine shape. I made up an adapter to flush each tubing independently and flushed it all out with clean water no blockages in tubing very lucky!
now its time to re-pipe with new boiler and components that i will need $$$$.
so I have attached a drawing of the basic piping layout, you will notice right away not all the needed stuff is included because I am a little confused to where the boiler pump, the boiler protection valve and how these two parts work together. I'm thinking going with Caleffi boiler protection valve and radiant manifolds. Am I on the road to getting this right?
V/R Don P

hot_rod

I would highly recommend separating the boiler from the Onix tube, or you may end up with a sludged system once again. I don't know what it is but some of those rubber tube systems, even with the O2 barrier still allow O2 ingress somehow, perhaps at the ends or fittings?

You can find flat plate HX on e-bay fairly reasonable.

Better yet an indirect, even a 20 gallon, to buffer those zones a bit.

Here are some piping options.

STEVEusaPA

You're going to need a buffer with radiant and multiple zones, or you'll short cycle, almost all winter.

don123

Thank You for you response, let me pick you brain, when installing the onix is it possible that when running the tube through the drilled holes in the joist you need to kinda fold the tube to fit it through the hole and maybe break that thin metal air barrier, would this maybe compromise the thin metal barrier? where the tube connects to the manifold adapter it seemed they were sealed tight couldn't get it off, so I had to cut the tube just below the adapter.
If I go with another indirect would this supply the heat source for the radiant manifolds only? Is this what the drawing is relating to as separating the radiant from the rest of the system? sorry i have a lot on my mind about this system cant think strait.
Thank You Don P

hot_rod

I wish I had the answer as to why some rubber tube systems sludge, some don't. I have seen them sludge, rust expansion tanks in a years time, even the latest version with aluminum and EVOH layers. The tube is so layered up that it is fairly constipated for moving the heat energy from water to floor. As such it takes higher SWT, which = higher O2 ingress.

Here is a pic of a sep from a local rubber tube job. It was installed on a leak-free system for 18 months and this is what it looked like! It jammed a few circs in that time period also. Two pin holes through the tube.

Yes, the pics show several methods to separate the boiler from the system. Everything downstream from the HX would need to be non ferrous, the circ and expansion tank.a

don123

18 months!! The picks that you show is what my circs, mixing valve, manifolds looked like. I'm now looking at the ss indirect to supply the radiant. My drawing doesn't show all need components but a basic start for my near boiler piping. Am I getting closer to getting this corrected. is there a caleffi video that goes into this type of set up?
Thank you for your input!

hot_rod

You have 3 high temperature zones? Indirect, 2 zones of heat emitters?
3- low temperature zones

You want to protect the boiler from low return
Separate the boiler from the rubber hose.

So the boiler, pump, expansion, piping can be steel (ferrous) metals, it doesn't see the rubber hose fluid, it connects to the coil of the buffer/ indirect.

Everything from the indirect buffer tank side needs to be non ferrous. I'd use two Grundfos stainless Alpha circs and zone valves. Use a 1" high Cv (7.5 or higher) zone valve on the indirect.

So all the "secondary" components from the tank side of the buffer indirect are non ferrous. Use a radiant type expansion tank from Amtrol, they are coated inside to protect from rust and corrosion.

Using zone valves will be less $$ than all stainless zone circulators, the Alphas work nicely with zone valves, or any stainless delta P circ of your preference.

The piping coming out of the tank side of the indirect needs to be large, 1-1/4 or larger as it is you "primary secondary" function, a low loss header. This allows all the pumps to get adequate flow regardless of which one(s) are running. You need an air purger and expansion tank on that secondary side also.

I think you just need one mixing valve for the low temperature, you show 3 way valves at all the manifolds?

If those are already in place, you do not need the 3 way mix valve back at the indirect. One or the others will get you mixed down.

If you can a single motorized mixer on the tank, so you can run the low temperature on outdoor reset control. The Taco I valve, perhaps.

The other option is leave the entire system as is, ferrous components and be very diligent with hydronic conditioners. They will need to be checked yearly, probably a booster chemical added. The oxygen scavenger in the conditioners will get depleted, used up, as it absorbs the O2 that must be entering somehow. Rhomar, Fernox, Adey all have test kits available to monitor the fluid.

The pros of the buffer/ indirect is both the separation of components and the buffer will help with all the zoning you have. You should get good boiler run cycles, best efficiency from the boiler.


This Idronics shows piping and wiring options.

don123

Thank You! I will look into the Idronics 17

hot_rod

t's a tough spot to be in.

A repipe to isolate and add some buffer will be thousands in just parts. Tank, pump extra purger and expansion, fill, zone valves stainless pumps, etc.
As much as I would like to see you pipe your way out of the problem...

The chemical romance may cost a few hundred to start. A cleaner, then good water with conditioner. It may be worth a couple seasons of trial?

don123

Hi Hot Bob,
As I'm a licensed Massachusetts Plumber by trade, I work for the DOD Airforce in mass.for the last 10 years and I'm not up to speed on all the new tech that's out there and don't work on much heating. i can trouble shoot heating systems but not design much. I can design and install domestic water and dwv not an issue. where I work we do have hvac techs but they only know repair and trouble shoot no one there has done radiant or mixed temps. so I had to look else where for guidance. I have been in the background reading heating help for a long time. thank you too you I have a start. Back in 2002 we did a major renovation to our home, and i thought radiant for the new part of the home. went to my supply house to have the radiant designed. they gave me the layout for the tubing but not the near boiler piping.
I have watch your idronics on tv, and its nice to put a face to a name! I have attached another drawing separating the radiant from the high temp. what's your thought? its kinda old school with new. I understand its going to cost $$$$. I assume that the chemical additive would be put into the radiant indirect. Thank you for your time.
see it the radiant is totally separate.

mattmia2

The idea is that if you use all nonferrous parts on the indirect that you are basically using as a big shell and tube heat excahnger and buffer tank then you don't need to treat the water. The talk about inhibitors was if you don't separate the radiant with the tubing that seems to be allowing oxygen ingress.

hot_rod

If the rubber tube is just in the 3 radiant zones then you are correct. You have just those separate from the boiler. Your indirect and high temperature loops are on the boiler side still. As long as there is no rubber tube in any high temperature piping you are good.

The difference in my piping drawing is that I isolated all the building piping from the boiler, high and low temperature and indirect.

what size is the boiler? How does it match up with the heat load?  If the boiler is way oversized the buffer will make a difference and you may go with a larger tank volume to extend run times

What you are trying to cover is when just one zone or a small load calls, you don’t want the boiler short cycling its brains out🥴 Andbin your case the added benefit of separating the piping from the boiler water

If you piped the entire system from the buffer, both high and low temperature zones would see the benefit of the tank volume.

Basically the boiler sees the buffer tank as its load, always. Whatever loads happen to be calling add to the tank load. When all loads satisfy the boiler keeps the tank hot and ready for any of the next heat calls. Once the tank temperature drops 20 degrees, the boiler fires to recover that and any loads that are on.

don123

The Boiler is 122,000. The rubber tube is staple up with reflective insulation. I'm sorry but I don't really remember what the heat loss actually is. When it was installed, the radiant for the first floor zone was delivering one temp. Some rooms were too hot, other rooms were too cold. The second floor Radiant zone also supplied one temp. The first floor radiant supplied around 120*(T-stat 67-68), but the bathroom and office were too cold ( 62-64*). The first fl. bath and office face north, with the office being over an unheated area and having a lot of windows. The office was cold. I found running the first floor bathroom radiant around 140* was good.
The second floor radiant heated a hallway, two bedrooms, bathroom, and another small room. The third bedroom is base board heat on its own zone. The two bedrooms and hallway were too warm but the bathroom and small room were to cold north facing. The two bedrooms and hallway radiant could run on the coldest day around 90-100*(T-stat 63-64*) we like cool bedrooms. the bathroom needs a higher temp water around 125(air temp 70*) to achieve this I closed of some of the loops to the bedrooms and adjust the mix mixing valve in the basement to 125* and the bathroom heated good. What I'm thinking is having the two bedrooms and hallway on one manifold (90-100*), the bathroom on its own manifold (125*)and the small room on its own manifold . This small room is North facing and needs about 135-140*. All the rooms on the first floor except the bathrooms are hardwood, the bathroom is tile. the second floor is an engineered hard wood the bathroom is tile. so I think I'm looking at
five manifolds. Three for the second floor, two for the first floor. here are some pictures of what used to be.

hot_rod

An infrared camera can be helpful for balancing all the various loops. You can do some balancing by adjust flow at the manifolds, but it is not a very linear change. Maybe crank the temperature to satisfy the coldest room on a zone and choke down loops or rooms that over heat. No carpeted rooms I hope?

Any room with a lot of furnishings that cover the floor can be hard to heat. Beds, dressers, overstuffed chairs, etc block the radiant transmission.

 Is the Onix 3/8”?  Hopefully the loops are under 250’ as the pressure drop starts to get high at longer lengths 

Probably 3 cv mixing valves, you may need speed two or three on the pumps for the bigger manifolds. 

If there ever was a Watts Radiant design done, it would have all that info.

don123

Yes, 3/8 Onix. The Taco circs were single speed. There are some thin area rugs in the rooms nothing thick over the radiant. four home run loops for the master bedroom, two for the other bedroom, two for the bathroom, two for the hallway and one for the small room/office on the second floor. On the first floor I have two loop for the office, four on the family room, two on the dinning area, two on the kitchen, one for the bathroom. The bathrooms, and office have no area rugs. I can take some pics if you like and PM them to you. The person who did the lay out didn't say what kind of pumps to use as far as I remember.
I really appreciate you sticking with me on this. V/R Don!

hot_rod

How old is the Onix? Did you flush it well when it was repiped? loop by loop? If performance had dropped off slowly over the years that may indicate they have some magnetite sludge in the tube. 

You need some good pressure to blast that heavy stuff out.  It is the ferrous metals breaking down that form magnetite, as such it is heavy, hard to move.  It settles in the bottom of boilers and the lowest loops in the system, see examples. A pressure pump or even house water pressure will help get a good flush. I like to add a hydronic cleaner, a strong detergent actually,  as that magnetite is also blended with pipe dope, solder flux cutting oil that may be in a new system.

Richard out in Colorado is saddled with many old rubber systems, that was one of the largest markets back in the day. He has flushed barrels of sludge out of those large home systems.  The higher the temperature the more they sludge as O2 ingress increases with temperature. So run as low as possible to get the job done. A good clean and flush will increase performance, in any case.

These are some of his pics. Some hose cut outs, a cast iron boiler section. In some cases various loops will get completely plugged ands need to be abandon. The air sep pic may be from Kevin.

Your return manifolds have a purge port, with a hose barb if you decide to do a loop by loop flush, it will be fairly easy.

don123

the Onix is 18 years old. The previous pictures are what was installed 18 years ago. over the last four weeks I have removed each loop from the manifolds and flushed each loop both ways I did the supply first with water then flushed it from the return with water then used air compressor to gently push all the water out and flushed again with water. I used a five gallon bucket to let the purged water dump into to see what would come out. there were no chunks or debris coming into the bucket just brown water. labeled what the loops go too I put red electrical tape on the supply and blue for return zip tie the supply and return together and went to the next loop. None of the rubber tube had any blockage just brown water. The manifolds, pumps and boiler took the brunt of it I guess. as of today 07/10/22 The manifolds, pumps and boiler have been put in a scrap pile. The Onix has survived. Ill show you the purge set up.

mattmia2

That globe valve boiler drain that i think you are using as a hose adapter is going to reduce flow a lot.

hot_rod

That fluid doesn't look too bad, rust mainly. When it is black colored "boiler ink" is a sign of magnetite. It settles quickly to the bottom of a bucket. It is attracted to a magnet. Like an Etch a sketch

don123

I'm fairly confident all tubes flushed out really good. there was quite a bit of pressure and water coming out the other side of the tube while flushing (house water pressure is 68 psi). When I first started flushing loops reddish brown water flowed out and then cleared up fairly quick. Definitely not black in color. so I think the tubing will be okay! Does heating help let us do short video's ?

mattmia2

You can't directly attach videos but you can put them on youtube or something and link or embed them.

don123

OK, Here is the boiler piping could I get your inputs?

hot_rod

don123 said:

OK, Here is the boiler piping could I get your inputs?

How are you mixing the 3 different radiant temperatures, 3 way valves at each? You can buy manifolds with mix valves and pumps built in, or build your own..

The upper expansion tank "radiant X tank" wants to be under the air purger to the left of the "SS Alpha circ"

don123

Yes, those are the ones I would like to use. I see they offer two different style pumps with this the 25-55U and ups15-58. Also would I use the hydraulic separator or remove the H. fitting that comes with it. Thank You. I seen the Caleffi video and was a little confused on when to use the hydraulic separator and when not required.

hot_rod

The 25-55 is an ECM Grundfos Alpha option.

That H sep at the manifold could be removed if you pipe the tank like this, upper scribble.
A large diameter pipe at the tank for both systems to connect. That "big" pipe, 1-1/4" or larger is the hydraulic separator function.

Piped like your drawing or my lower, you need to leave the H sep in the manifold. Your loads are parallel piped, not P/S.

Your tank may have top connections? Doesn't matter where they are located, just increase them to 1-1/4. Use an indirect with large tank connections, if not a fitting increaser right at the tank. If it has a dip tube, maybe use the drain connection instead, to avoid the reduction in the dip tube.

For example, if the tank is 3/4, use a 3/4 X 1-1/4 fitting or a swage nipple makes a nice smooth transition. They come in all sizes.

Maybe these tank drawings from idronics 17 clear up how the separation at the tank connection is working.

Here is a 6 gallon tank I used to make a buffer. The side connections were 3/4" So a 3/4 male x 1-1/4 copper adapter for the increase.

Also an example of how I increased this small electric tank to use as a buffer.

don123

Would it be safe to say I could use a 11/4" brass tee with a 3/4" F x 1/1/4" M brass bushing? The temperature and pressure relief valve needs to be installed at the outlet of the tank. The tank has top Side outlet and the cold water inlet at the bottom of the tank.

don123

Here is the revised pic do i need the check valve in this location?

hot_rod

Of all the options this best covers your objectives. Take the bb zones and indirect off the boiler loop. This way you don’t need to run the buffer at 180f to cover the indirect and high temperature zones. It will allow the indirect DHW tank to have the fastest recovery also, 100% flow from boilerto tank on priority. Run the tank at 140f, the highest temperature the radiant zone requires. No need for any mixing valve on the 140 zone. So just 2 mixing valves needed.

Circulators all come with check valves in them now, so no checks needed.

Really all you need is a 30 psi relief, like the boiler has, in the tank, no need for a 210 degree, 150 psi T&P valve.

The indirect usually have 1” or larger connections, so not as much as a increased needed compared to using the tank 3/4” connections for the large header pipes,increase to 1” to supply the radiant zones off the tank, 1-1/4” for the short pipe section at the indirect/ buffer connections

don123

Ok, I assume the boiler pump 007E that came with the boiler can be used (pump1)? Pump 2 could also be C.I. 007 for the BB and DWH ? I'm thinking to use another dirt mag on the radiant return. Boiler Pump (1) should run on all calls? Lets say pump 2 ( BB or indirect) turns on pump 1 will run? If radiant pumps are on The boiler pump (1) may not need to run unless the aqua stat on the heating indirect calls for more? Is the auto fill needed? I assume it does to flush out the dirt mag on the radiant. maybe over kill but...

hot_rod

The 007s should be fine.
Use a dirtmag on any system that has an E or ECM circulator
Use a relay box to run all this, Caleffi for example. Probably a zone valve 4 connection so you have a spare.

Several ways to control it. Have the aquastat in the buffer tank connect to boiler TT, so the boiler always has the tank warm and ready to heat the radiant

The boiler pump relay turns on the 007e

The radiant zone pumps wire to a zone pump relay box, the Caleffi relays connect to one another with a 3 conductor t stat wire to communicate. Since the tank is always warm, that system. Is done. You ugh the switch that system off in. Summer months, or run the boiler on ODR

The high temperature run through a zonevalve relay box, zone 1 on Caleffi boxes is always the priority, so indirect ZV goes on 1

TT from that relay box also goes to the boiler, so when a high temperature zone calls, it will fire the
boiler. The buffer tank may overshoot when DHW indirect calls. Ideally the DHW indirect would pipe and pump to take all the boiler output, nothing goes into the buffer, and you recover the DHW as quickly as possible.
, buffer would not over temp, if so.

I’m not sure if the buffer will over temp when high temperature zones run by themselves. Of if it is ever possible that high temperature zones run and not low temperature at the same time? If so, the tank may rise above 140,and you would want 3 mix valves on the radiant manifolds.

With a buffer the hotter you run, the more storage and longer runs without firing, but a bit more stand by loss from a hotter tank.

don123

Yes, I'm going to get the ones with the mixing valves regardless, just incase something goes wonky. since I'm going with the Caleffi manifolds what are my options on connecting the Onix to the manifold?
As for the radiant zones I will reuse the 4 zone pump relay I was using before. I was eyeing the ZVR104 for the high temp zones thank you for the reassurance on that. The boiler came with the 3250 + and I would like to use the outdoor reset option. Going back to the manifold pumps they have two types are these variable speed or one speed and which could be my best option. Thank You!

hot_rod

Did you happen to save the manifold adapters from the stainless Watts manifolds? Watts is the only one I know that has Onix barb manifold adapters. I believe that manifold has 3/4 conical branches and those adapters should work on a Caleffi. I have some old Watts manifolds and adapters kicking around, let me confirm that.

Supplyhouse.com shows that Onix adapter SKU689001-10 a ten pack, (out of stock) hopefully you still have them and the spring clamps?

ECM circ if you are going to use actuators for sure. if not either circ. I like ECM for adjustability and energy savings.

don123

Yes, I do still have them. I will see if I can buff them up and see what they look like, I'm a little OCD. Are the EMC pumps manually adjustable speeds? It looks like they have a red circ and a gray circ with their manifolds.

hot_rod

the red pump is the 15-58, standard efficiency 3 fixed speeds
Silver is an Alpha 15-55 hi efficiency ECM 3 fixed speeds, 3 proportional speeds used with zone valves, zone actuators, or TRVs

Officially Caleffi does not offer Onix adapters
Off the record they fit the Caleffi S1 manifolds fine
The seal is made by that “nose” o ring. Check yours, maybe even replace them. Hydraulic and hose shops have o ring selections, most automotive places also. Possibly but unlikely watts offers new o rings.

don123

Ok, looks like I will go with the red 15-58 circs. Thank you for checking to see if the adapters match up. I will look at the O-rings, take them off, if they don't break and I see no rot or cracks ill use some plumbers grease and lube them up and reinstall them back on the adapters. Than you for your Guidance, Knowledge, Time, and the love of what you do! Its going to take some time for me to put this all together but I will get there over the next few months. V/R Don

hot_rod

Sounds good. Look for dry or hardened o rings. A good o ring should feel slippery dark colored.
Some plumbers grease on the nose and also the brass threads helps everything slip together. Not much force when you tighten, a bit more than hand tight so you don't crush the o ring.

If you are a toolaholic

don123

I went to my supply house today and they have the onix adapters 10 pack pricey a little more than supply house but in stock. I looked into my existing ones on the manifold, with a supper thin putty knife I was abele to peel the O-ring off and they felt ok but I think they may have stretch a little and didn't really fit back on too snug a little sloppy and the black was all over my fingers that's telling me it will be a no go. I will need to bite another bullet. I'm on vacation this week!!. I looked into the indirect heater they could have it in on Friday. Thank You.

hot_rod

which indirect are you looking at?

mattmia2

Harbor freight and lots of other places sell line wrenches too.

I have found the online o-ring web sites a great place to get exactly the size o-ring you want in a material more resistant to what you're dealing with than what the manufacturer originally used.

don123

I was looking at the HTP ultra max indirect

don123

I thought i sent PMs to both of you? mattmia2 thanking you on clarification
and hot rod the cut sheet on the indirect? I'm not to into computers. don't you go to the little envelope type the name and send?