Anyone Familiar with Noritz Boilers?

[coolpool]

I installed in floor heating in my garage and the direct fired boiler (glycol) is made by Noritz. It worked great for one day now it has a bad 'resonance' (sp) coming from the watertubes. If I pinch back the flow a little the sound diminishes but then the low flow cutoff shuts down the burner. Any ideas? This thing was as quiet as a church mouse when it first ran. I did go through the manual, but it only has troubleshooting for error codes. I think the ratio is around 50% or less; It's good to -18C. The noise is very loud but it does not shut down the system. It was in service for one day. A professional plumber installed it. It's all copper.

A little more info; the main circulating pump(on the right) is a variable speed model for efficiency. The floor circulating pump (left) is a three speed model set to the middle speed (85w i think). I have tried adjusting all the speeds and manual zone valves. No change in the noise.

[atc007]

As a prolific do it yourselfer,,YES,,you want to KNOW and,understand exactly what's going on... But hold the fire under this"professionals" butt !! Make him come fix it,and don't let him sleep till it is all right! And watch him,and have him explain what's going on ,and how he's fixing it. My .02. Good luck! Nice setup btw,,my sister in Fairbanks just bought a speechlessly gorgeous log home up there with 100% in floor heat.. We'll know in the spring how they like it...

[coolpool]

As a prolific do it yourselfer,,YES,,you want to KNOW and,understand exactly what's going on... But hold the fire under this"professionals" butt !! Make him come fix it,and don't let him sleep till it is all right! And watch him,and have him explain what's going on ,and how he's fixing it. My .02. Good luck! Nice setup btw,,my sister in Fairbanks just bought a speechlessly gorgeous log home up there with 100% in floor heat.. We'll know in the spring how they like it...

I hear ya ATC. Unfortunately this was one of those deals where I built him a 18' interlocking stone fire pit and he installed my heating unit for the cost of parts only. He didn't even wire it up; I had to fiddle fudge around for a wiring diagram for two weeks; don't get me started on that. I found this on youtube, http://www.youtube.com/watch?v=80vBv1c0QSo and that is the exact noise except mine is worse. I'm leaning on that my gas supply pressure is too low causing the flame to sputter. This makes perfect sense since it takes almost a minute for the sound to start once the burner ignites. The installer was a little concerned about the size of my meter but it seemed that we had good pressure at the shop at the time. For the record, there is approx 130' of gas line to the unit.

[Dirtcrasher]

I imagine a 3/4" line or larger would be enough, although the spec is what it is.

Any chance it has some air in the system?

We use to do Veismans hanging boilers like yours, super efficient. One time my boss bought cheap "NOT RECOMMENDED" tubing and it made all kinds of strange noises.

We had to rip it all out; Cheap boss!

Wow, just watched that vid, sounds like a Harley I hope you have sufficient gas being brought to the unit.

[jeswinehart]

Judging by you pinching the water line down a wee bit diminishes the sound and after listening to the youtube sound, it sounds like air in the water pipes.
Fresh water has alot of air in it and if I take my house system down, I get air out the manual bleeders for a week.
I don't beleive that sound is from low gas pressure. When the flame ignites off the orifice(s) it generally has more of a jet sound and once started, don't "normally" go back and forth.
Although, a 130 foot run of 3/4 inch gas pipe is only going to get you around 146 thousand BTU at the end of the pipe (on propane ~ figure about half the BTU for Nat gas), you won't know until you put a manometer on the manifold side.
How many BTU and on what fuel is that unit ? Just curious is all, I still think there is a small amount of air in the system.

[up-tyte]

It looks like you may have it plumbed incorrectly. In the photo it looks like the supply and return lines to the manifolds are coming out of the same pipe, the two tees in the middle of the picture. The floor supply should be coming out of the hot and the return in the cold. There should be a check valve on the incoming water supply line,(the black hose coming from the floor?) and the other check valve should be on the return line. I don't understand the two pumps the diagram I have only has one on the return (cold) side and the expansion tank is on the supply (hot) side. Also make sure you have the correct glycol/water mix based on your lowest Ambient temperature, if that is your 50% then its correct for -22F. We have installed several of these on the homes I build and use them for potable water, we haven't use them for radiant heat yet, but they are very temperamental when it comes to hard water and water with a high concentration of particulates. Make sure you filter the water going in. You can also try the Noritz website for a drawing, www.noritz.com/trade. Hope this helps and let us know what you find out.

[Thorpe]

I agree with jeswineheart and dc... Sounds like water. I would look at the air seperator first. Sounds like air in the system...

[hoosierlogger]

That looks like a plumbing nightmare.

[CRAZY70MAN]

gas or propane?? 130 ft of what diameter pipe? Any elbows in service line? You mentioned sputtering flame??? Volume is relavant to your btu. You may have undersized service line or obstruction in the line and or regulator if it is indeed regulated pressure. Does this line feed anything else??? Give us some more info on your gas service situation??? I work in the gas industry for a living. Hope ya get it fixed..gonna get my floor heat in this spring. Lots of variables when calculating line size for appliances. Sounds to be more in the liquid department of the system at my first guess though.

[coolpool]

Thanks for the tips. I'll try to answer all above questions. The line is 1" from the meter to about 20' from the appliance and the fuel is natural gas. The last 20' is 3/4". This is a dedicated line to the shop, no take off's. This is a direct fired unit with a glycol/water mix in it. I checked the data plate and it's rated for 163,100 BTU/hr. All that for a 970 sq/ft shop? Holy overkill Batman! I'll have to get a monometer as the min gas inlet pressure is 4" W.C. When I first started it we did get a lot of air out of the auto expellers even though we used an external pump to fill, flow through and pressurize the system. One of the first things I did when it started making noise was to drain some fluid into a pail to see if there was air trapped. When the pumps first start flowing before the burner kicks in it's super quiet. Only after the burner comes on does the resonance start; slowly at first then increases at a steady rate. Here is how the thing is supposed to run.
1 - The thermostat calls for heat to the zone valve (bottom left)
2 - The zone valve opens up and starts the pumps
3 - Once min flow is established, the burner ignites
4 - When setpoint is reached the zone valve closes shutting down the burner and the pumps

The pump on the right maintains flow through the tubes and has a flow switch in line
The pump on the left takes its flow out of the mainstream and discharges the cooler fluid back into the mainstream; mixing it if you will

I will be having a heart to heart with Noritz tomorrow.

[jeswinehart]

Pete, your piping size is good to go. it is a very good thing you have the 1 inch main trunk line stepped dow to 3/4", some body done their home work there.
That will most likely be the first thing a tech will ask you, what the gas pressures are
(incoming side he will want to know lock up + flow and on the manifold side ~ after the gas valve he will want to know the flow when unit is running), I don't reckon you will get much more out of him/her until you can answer those questions
(they always blame the darn gas companies and regs/pressures for some reason)
You can build your own water manometer really easy if you have a stretch of clear tubing and 2 rulers. Just for a point of reference, that is what I still use today and what is HIGHLY recommended to use to "frequently test" all the other digital or pressure gauged units against for accurency (no, mine is store bought manometer)
PM me your phone number and I will call you tomorrow night if you need any more info on how to do it (I get free calls to Canada so no worrys there)

[RoscoW]

Is your expansion tank charged properly or waterlogged? If your tank does not have the airspace for the expanding fluid to go then the pressure relief valve may be opening? Where is the expansion tank plumbed in? It kind of looks like it is attached to the pressure relief valve which should be free to drain ?

I should also qualify that I have no experience in hot water systems other than the one in my house which I have become very intimate with LOL
Ross..

[coolpool]

Thanks for the encouragement folks. The saga continues. The gas pressure will be checked this week. I called Noritz and they immediately said it's being caused by microscopic air bubbles entrained in the glycol/water mix collapsing on the exchanger surface during burner operation. They recommend a boiler additive to correct this. I also talked to the guy who designed the plumbing for the system and he said the pumps should be swapped around. When I pulled a glycol sample out it was cloudy indicating air entrapment. The Spirax air eliminator is supposed to remedy this. Wonder if it's pooched? This is why I drink...lol. Thanks for the offer jeswinehart, PM sent.
RoscoW I have no indications that the expansion tank is bad. I suppose there is a weep screw to check? Also the TP Valve (Temp/Pressure safety valve) is plumbed to grade. If we were overpressurred, I would know immediately. Just talked to another boiler rep and he recommends 'FURNOX'. It's an air scavenger; so he is agreeing with Noritz.

[Dirtcrasher]

I had to fix a Burnham boiler a few weeks back. First thing they said was "are you a certified Burnham Tech;" To which I replied, well, we install these things amongst other equipment all the time. Then she gave me tech support. Once I got him I offered a friendly greeting and immediately got to the point and said enough that he knew I wasn't a bean head homeowner (although I knew nothing about this particular aquastat ) It seems to help.

Sometimes the guy on the phone solves the problem very easily if he knows you have half a brain and are polite and somewhat knowledgeable.

They will ask specific questions such as model/serial number and the gas pressure incoming and out going when at full flame. Or in my case it was "second stage of heat". All similar but different.

Thats a nice system, you'll be happy once it stops annoying the heck out of you. Plumbing it is the easy part, it's solving the silly issues that can be a PITA.....

[coolpool]

Agreed DC, good advice. They probably hear alot about 'thingy's' and 'Do-Hickeys'. I'm familiar with the purpose of all the hardware that was installed and can talk with confidence to folks that are trying to help using correct terminology. I've received lots of good suggestions and will hit the boiler again tonight. Here a pic of the baby steam gens I run at work, lol. The good thing that these have is wiring diagrams, instrumentation diagrams, engineering specs and control naratives. My little guy, not so much ;-) One positive that is coming from this is that I'm learning a heck of a lot about Hydronic heating, so it's not all negative from my perspective. I'm amazed at the diverse background fellow forum members have. I guess it's easy to forget that we all must serve someone to afford our little habit.