Primary Secondary Problem

heatpro02920

My tech went to a service call this morning, its a new install, customer did it himself, the problem is now that isnt using heat he is having problems with his hot water. Its an alpine boiler piped pri/sec

The primary for some reason is piped 1 1/4" and the secondary tees coming off of it are 3/4" feeding 1 zone and the indirect water heater, the spacings are all correct {except the the 90s are a little close to the closely spaced tee, thats what my tech remembers but we have put them closer, I have come out of the close tees with street 90s and the system still works.

My first thought was the odr, but my tech said the temp is going to 175...



Any thoughts? I want ot just repipe it but the customer would rather not of course, since he did it himself....

Paul48

175

Are you getting 175 to the indirect though? Or is that merely at the boiler, and because of the pipe configuration, he is getting reverse flow between the tees? Piping contrary to the rules may work, but you may sacrifice efficiency.On any of your installs that you used street 90's, would you notice 5% of the heat not going to the zone?

heatpro02920

When I

used street 90s out of the tees, I used delta t circs so they took what they needed from the assembly, I never noticed it ran longer or anything like that, the temps show the same results as if I spaced them by the book.. Now obviously if I could have spaced the correctly I would have but there was always space restraints forcing me to make due...



My tech said he had 175 going in the tank and 160- returning. But was off all night, he didnt try to run it with the heat calling..



I just spoke to the customer, I told him the price to repipe it and he more or less wants me to tell him how to do it, he paid us for the service call, I told him follow the instruction manual... Some of these customers I just dont understand, if you can not do the job don't if you can by all means do...

CMadatMe

My Thought

What size Alpine an I'll give you my opinion. What size and brand is the tank and what's the secondary pump and/or indirect pump?

Paul48

Maybe

This problem only pops up once in 20 installs, and maybe it is not the problem at all. But, it forces you to go back to "the book". If you know the supply temp from the boiler is the same as the supply temp to the zone or indirect, then the piping is having no effect.

heatpro02920

alpine 080

and pump is a 15-58, indirect is a weil mclain 40 gallon my tech says every pump on the system is the 3 speed brutes, I believe they are ups-15-58 fc ?

Robert O'Brien

Indirect

Piped off primary or secondary?

CMadatMe

Sorry Heat

One last question I forgot to ask. What was the return temp at the boiler? I'm assuming the indirect is piped as a zone off the secondary side, correct?

jonny88

secondary zone

is the indirect piped in 1 inch or 3/4

heatpro02920

PIndirect is piped off of the

secondary, the customer called back and said he tested his water at the faucet it is 92 degrees... I sent my tech over and it was 110 but the aquastat is set at 140....

Ironman

Aquastat?

Might simply be a bad aquastat.



You need Delta T readings from both the hydronic and domestic side with the tank uncharged and the gpm measured. Then use the universal hydronics formula (btu= Delta T x 500/gpm) to calculate the output. If it's not near the rated output of the boiler, then you have a hydronic problem.

CMadatMe

It's a Condensing Boiler

Need to know the boiler supply and return temps on the primary side. We know supply and return on the indirect 175 - 160 or 15 Degree Delta-T based on Heats post.



Heat said 1-1/4" Piping primary, 3/4" Piping Secondary. If your not pulling the btu/hr, ie flow out of the primary and it's flying to the boiler return the boiler is going to stay in low fire and that's 16,000 btu/hr Input.



The boiler flow if we use the manual is 7.3gpm, Can we all agree the indirect flow is 4gpm due to the pipe size? If so,



(Boiler Flow - Sys Flow) *Boiler Supply + (Sys Rtn Flow)*Sys Rtn Temp / Boiler Flow =



Boiler Return Temp



(7.3 -4)*175 + (4)*160/7.3 = 167 Boiler Return Temp



175 - 167 = 8 Degree Boiler Temp Rise



7.3 x 8 x 500 = 29,200 Btu/hr



29,900 Btu/hr / (90-50 x 500 ) = 1.46 gpm recovery When the homeowner called you..



29,900 / (15 x 500) = 3.98gpm through the indirect zone or 4gpm in round #'s



The solution. Pipe size on the secondary and to the indirect needs to be 1" so you can pull the entire 7.3gpm across the indirect and get your delta-t out to a 20...

heatpro02920

I am personally going tomorrow

to check it out, the answering service just called me and said he left 2 messages, who is checking there hot water function at 11pm? I will pick up a service truck in the morning and swing by to check it out... Im going to see the problem as soon as I put eyes on it, there is no doubt about that, even my tech said he knows its going to be something stupid he didn't check... He is upset because he hasn't had a call back in 68 days the record for a full time tech is 73 days and he gets a $500 bonus {I have the Evron ESP software, keeps track of all that stuff, great incentive for anyone with multiple techs to do a good job}...



But anyway, tomorrow will tell, I charged for 1 service call and have been there twice now, once in overtime, so I have to get this straightened out... If it does indeed need to be repiped which is possible, and he doesn't want to do it, I'm not a magician, and I'm not working for free...

Tom_133

Tough to know without seeing it

Heatpro I think you are doing the right thing, I read this thread and came up with 10 possibilities, Chris covered a few of them. Without being there seeing it and doing the testing they are all just guesses. Let us know what you find.

heatpro02920

Problem solved...

So I get there at 7:30a this morning just as his wife is getting in the shower, I took my Flir thermal imager with me. Here is what I found, keep in ming this is the first time I ever seen this with my own eyes, just had bits of info from my tech...



The unit is piped Primary secondary, fired up the t-camera and watched the system work, the hot water left the tank cold fresh water entered, the boiler fired and started circulating, then the heat went to the indirect, the pipes were all turning white and everything looked good UNTIL...



About 3 minutes into the cycle heat started moving up one of the zones returns which is a 1' copper supply and return to a garage modine unit and the temp in the shared supply started to drop.... What is happening is the system is building pressure and pushing by the single check valve that is in the circulator which is on the return line...



Hres what I wrote on the invoice, I charged him for going there today and he wants to fix it himself..

"System needs to be repiped, circulators moved to supply, needs larger expansion tank installed, and check valves installed on returns. I got out by designer book and drew him a fast cartoon of how it should be done, he actually seems like a decent guy, just over his head. I can not understand why he didnt just follow the manual, but he did as little piping as possible... Also his water quality is terrible, and installed a hot water filter that is almost clogged {I dont like them, he has one of the outdoor wood boiler plastic houseing filters on there, I gave him the calleffi part number for there unit, also had no air scoop at all.. Just everything wrong... I drew him the pics, and called my supply house so he can go in and purchase/pay cash without an account...



I'm not going to mark this as a call back for my tech, he told me "everything is wrong" when I asked him, and he was rite... Its just wrong.... He got hot water when it was heating season because everything was hot, but now that the water in the lines its cooling the indirect....



Thanks for your ideas guys...



PS if anyone has been thinking about getting a thermal imager for their service trucks, dont hesitate they are awesome and the prices are very fair now, Flir I7's are under $2000, I have 4 of them and they pay for themselves in short order..

CMadatMe

Hmm

Thought you said the secondary was piped 3/4"?

Jason_13

Close spaced tees

I thought the spacing before and after the tees is important. I read somewhere the distance before should be a minimum of 8 pipe diameters and 4 pipe diameters after the tees.

Gordy

Design rules

Can be deviated from, and still work, but work best if design guidelines are followed. As heatpro pointed out earlier.

heatpro02920

Gordy hit the nail on this one

The design rules are always best followed to the letter, But in a situation when you A can not possibly follow them or B could but the materials and labor would out weigh the benefit, you have to let your experience and general sense be your design rule..



I have of course seen closely spaced tees not work correctly, but most of the time that is because they put something in the middle of the tees I seen 2 st 45's throw a monkey in the wrench, even a full port ball valve {although webstones purge tee setup works and has a ball valve, but inside the casting is a weird relief they machined that i think has a lot to do with it}.

The most important rule is the close tees, make them as close as possible and dont put anything in the middle... Now I have seen a 1 1/2" Pri sec with 14" between the tees that worked for 30 years, so even that can be tampered with to some degree... but it is always best to follow the rules, for peace of mind if nothing else...



I have done a few with street 90's including my own home, and my tech was shaking his head the entire time I was soldering it up, saying "you can NOT do that" but it works just fine... Think of it this way the water is going to follow the path of least resistance, and when the secondary circulator is flowing and the primary circ is flowing the secondary circ has to get its fluid from somewhere, and having positive pressure on its side of the cst's is the perfect place for it to come from, so it takes it simultaneously depositing it into the opposite side of the cst (I hope I explained that rite), so unless you created enough turbulence to disrupt your pumps flow you will be fine, now say the system does not work, you have a couple options its not the end of the world and you aren't leaving until its done rite.. A stronger pump may work or repipe it the correct way...



if you have to ask, then your better off doing it rite, if you have the experience not to have to ask, chances are you are it'll work...

SWEI

If you actually have the experience

it includes a few unforgettable failures from which you finally learned WHY.



Having years of experience but never actually asking why can cause all sorts of trouble.

heatpro02920

A few Swei?

I can not count how many times I learned the "hard way" in my life time, luckily there wasn't a lot of people around to point it out and laugh, and no one got hurt, lol...



It applies to everything, I build motorcycles as a hobby, and about a month ago, I finish a chopper I have been working on for about 3 years {monster at over 9ft long, 330mm rear tire, 113" SS w/parts acc. right side drive 6 speed, ect, if that means anything to ya, lol} when the weather started to break, I said I want to bang out the last few things I had to do. I had about 3 hours of work and set aside a sunday to do it. Alll done, I throw a helmet on and take it for what I call the "maiden voyage" this is where you have no fun becuase you are looking for loose bolts, timing issues, adjustment issues, ect, since this entire vehicle started life in my shop as 31 boxes of parts and a frame in a crate, then after a 1/2 lb of welding wire and 100 hours of labor you have a motorcycle...



Well long story short, its running perfect, nothing to tighten {although I always bring my back pack with tools in it just in case}, instead of heading back home after I hit the end of my neighborhood, I said "ehh, screw it, I havent ridden in 7 months, I'll hit the high way go by the shop with it and grab the mail off my desk" About 9 miles later I pull the clutch in to shift and it felt wanky... now I notice a smell, this is bad, if you are on a motorcycle and going 50 mph and can smell something, NOT GOOD....



I NEVER added primary fluid, I filled the oil, tranny fluid and needed to buy more primary fluid, which I did but was still sitting in the back of my wifes suv, it had rolled under the seat, and I said I would get it later, which I NEVER did..



So I learned the hard way, I pushed a 700lb 9ft+ chopper, with wide handle bars that are only about 35" from the ground over 2 miles to my shop, I could have easily called one of my workers, or my brothers, or my wife and kids for a trailer that own 5 of, but I figured this would teach me and I will NEVER forget primary fluid again {plus I didn't want to sit there next to my broken bike watching people drive by}..

I actually took the primary apart last night {hence this being on my mind} for the first time since the ride, and its not pretty, the only stuff I can save are the cases, I'm going to need clutches, chain, seals, ect, Probably about $1100 of parts...



So anyway learning the hard way is going to happen every now and again, even when its somthing you already know, if I wasnt lazy that day I picked up the fluid and reached under the seat for it, I would have put it on my toolbox and it would have been rite in front of me, I would have filled it...

Jean-David Beyer

Having years of experience but never actually asking why can cause all sorts of trouble.

I'll say. This was shown to me decades ago by a woman where I used to work. She was a computer programmer, and I was doing programming at the time too. She allegedly had 12 years of experience, but she was the worst programmer I ever met in my life and she thought she knew everything. Her programs would run 1000x (I am not exaggerating) slower than they should have.



Actually, she did not have 12 years of experience. She had 6 months of experience 24 times and never learned anything from them. Fortunately, she left the company to become a nun. I hope it was a contemplative order and did not have to interact with people.

heatpro02920

That is what happens when you get explained something over the phone.

I never seen the system until I went there to check it out, I thought there was one zone when they was more than one. So I was relaying what I was told by my tech...

I asked what size the zones were he said 3/4, whicih the house zone was, but the garage zone that was snuck out on the side of the boiler off the same tee that went to a boiler drain too and is 1" to a HUGE hanging unit in the garage {this guy got it off c-list, it has to have 3" taps in and out of it, I didnt crawl up there to check but I would say its 250K BTUs and has to hold 30 gallons of water, lol... just insane, the fan is going to use more electric than an electric heater sized properly for the garage would use...



But yes, it had a 1" loop for that garage heater, I didn't even ask my tech if he noticed the garage unit. they can not be trusted, lol otherwise they would be in usiness for themselves....

I once went to a service call that 2 of my guys couldn't figure out {only 1 of which still works for me now, it was a while back} that was a wood burning outdoor unit piped into a utica oil fired boiler... The problem was no heat once and a while, I specifically asked them what kind of wire feeds the boiler and to trace the wire back to the panel, and they said they did it was 3 wire romex inside BX, I get there and the feed is just romex no casing and it feeds off of a box about 10ft away from the fireomatic, someone wired light switches on the basement lights to get rid of pull strings, problem is this fed the boiler, lights go out, boiler goes out, took me 5 minutes to figure this out... My techs were there for 2 hours... They cleaned the boiler, changed the transformer, and purged the system... I was like ****????!!!!!???!?!?!?!?!?, how do I bill this?

SWEI

Experience

My line goes something like:  And I have the bite marks in my @ss to prove it.

Gordy

Ahh life's journey

Some choose to learn from their mistakes others choose to forget their mistakes, and relive them over,and over.

SWEI

Learning from mistakes

Did not come naturally, or even willingly in many cases.  I really am getting better at it, though...

Gordy

Believing your wrong

Is the first step. Second step is admitting it. Third step is retaining it mentally.

Paul48

A visit to Joe's garage

Some scientists claim that hydrogen, because it is so plentiful, is the basic building block of the universe. I dispute that. I say there is more stupidity than hydrogen, and that is the basic building block of the universe.

Frank Zappa

Gordy

Stupidity

My favorite saying when paths are crossed Is.....you need people like that to make people like us look good. Otherwise what is there to compare to.