Tankless does not maintain boiler temp after propane line change.

[Shibby021]

This is for hydronic floor heating in slab, heater is Hydrosmart 120, its setup for propane. not even 1 year old unit yet.

I installed this system and ran it while I finished building the house, the 500 gallon tank was sitting right by the building with half inch copper line. It ran great no problem love it. However it was time to move the tank 60 ft and I installed propoly 1 inch gas line underground and connected tank 1st stage regulator to line with half inch copper 34 inches long. At the house I put half inch copper 24 inches long from line to 2nd stage regulator. I tested the pressure at the tankless gas valve and it is at 11 inches wc, spec says 8 to 13 inches wc.

Now it doesn't work, barely will run at 100 degree boiler temp. If I run it at 140 degree boiler temp, the unit seems like it's gonna blow up, it was making so much noise and then it throws code 510.

I was able to get it to go at 120 degree by opening the mixing valve about 30-40 degree open, but the gpm drops from 2.5 to 0.9, it took all night to rise house temp 1 degree from 60 degree. Yes it's cold floor, its been few days since it last ran.

Any suggestions what I should try next? It seems like it can't handle 63 degree inlet water temp now...

***UPDATE**** added video

 

[Fitter30]

Have 11" at gas valve while heaters running? Look at the gpm at heater.

 

[Sponsor]

 

[Shibby021]

Have 11" at gas valve while heaters running? Look at the gpm at heater.

yes while running, however it does jumps up and down from 9 inch to 11 inch depending on the position of the mixing valve.

When mixing valve is closed it is about 2.6 gpm, when opening the valve it goes down to 1.1 to 1.3 gpm, that's where its much quieter.





I have checked all connections, and wiring, all look good. intake and exhaust are clear.

The flame as I see through the flame window varies all the time. mostly yellow/orange on tips

Temp spikes from 93 degree to 135 degree when mixing valve is closed and boiler set at 120 degrees.

Boiler runs better when mixing valve is partially open and temp set at 100, but the hot side pipe to the floor is cool due to cold side is mixing it, so pointless to run that way.

I can run it at 100 degree with valve closed but it's noisy and i can feel it through the walls. but occasionally throws code 510.

 

[Shibby021]

***Update*** i took the flow sensor out and there was no damage to it from the screen breaking apart. So I do not think that the screen breaking up is the cause of this. I think its gas related.


While reading through parts diagram, I noticed there was a screen for the cold water, I took it out and it's been torn out, I can still see bits of screen but 90 percent of it is gone. So I am guessing its jammed somewhere up there. Oh boy now what do I do? Is that the reason of this issue I'm having?

 

[Fitter30]

Why do u think u need a mixing valve? The heater doesn't know if it's pitching or catching with the volume of water keeps changing. Raise temp of the mixing valve see how the temp changes. What brand and model of heater? Though screens are tough never seen one in pieces. Doubt if the screen would pass through the heat exchanger because of the small passages.

 

[Shibby021]

I looked at few systems before I built mine, and they all had mixing valve so I added that. It's always closed though.

Raising temp to like 140 makes the unit shake violently, like little bombs going off inside there but rapidly in sine wave, and it starts to exhaust out of the unit which makes the room very stinky with propane exhaust.

I decided to go and fill up 100 lb tank again as I used that last year and it worked at 140 degree flawlessly. I just finished hooking it up and its running whole lotta different than it was on 500 gal tank running at 120 degrees. A lot more lower rumble still sine wave like. Lasts much longer before it finally kicks in the code 510. Running at 100 degree seems almost normal but still sine wave rumbles going on very low tone though. It's currently at 105 degree and running with no code so far.

Boiler is Hydro Smart 120 Plus , 120k btu condensing boiler from Menards.

 

[John Gayewski]

Can you raise the second stage regulator from 11" to 13"? Those boilers are cheap pieces of junk. But it should still run better than that. Not being there I can't say for sure but I think your confusing the equation by adjusting the water temps and mixing ratios and adding that to the descriptions. There should be a testing feature (on a good boiler) that'll run the gas valve on high fire and low fire on command while you watch the flame or monitor the gas pressure.

 

[Fitter30]

This is a chart for btu vapor pressure and temperature.

Propane Information

Propane Vaporization Chart, Properties and Combustion Data VAPORIZATION RATE - 100 lb. Propane Cylinder (Approx) Pounds of propane in cylinderMaximum continuous draw in BTU/hr at various temperatures in degrees F. 0° 20° 40° 60° 70° 100 113,000 167,000 214,000 277,000 300,000 90 104,000 152,000...

www.google.com

 

[Shibby021]

Last night while sleeping I was awaken by the smell of propane (my space is a 40x48 wide open bachelor pad) I saw that the boiler was off, meaning room temp has reached set point. I ran over there to shut off the gas, vented and went back to bed. This morning I turned the gas on and found it was coming from the boiler. I suspect the gas valve is bad. Code 510 is "Abnormal Main and Solenoid Gas Valve" I will have to call Hydro Smart tomorrow morning as they are open Monday- Fridays. Hopefully they will allow me to drive down there (they are 2 hours from me), and swap out the gas valve or something the same day so there's no heat down time as the real cold is coming really soon.

I have a question, so I build this system in a hurry this last January, I filled it with well water, yes straight well water no antifreeze. I just didn't see reason of needing antifreeze if it's always going to be warm inside here all the time, I have Kerosene heaters as backup. Some locals think I am crazy. Am I? Should I add some antifreeze? I just don't like antifreeze has it reduces thermal efficiency and its just bad for things. There is 2 inch foam under the slab and around the perimeter.

About the mixing valve, It's a term I used to name the valve on my friend's hydro smart integration panel system he bought as kit from them. I ran into information about that valve while doing research on my issue, that valve is actually purge valve. My friend bought kit system from Hydro Smart that came with prebuilt panels where you just mount it and hook up pipe to each panel, manifold, boiler etc.. then heat on.

That purge valve is supposed to be closed while filling up the system then it is to be left open during normal operation. That part about leaving it open really messes with my head why it has to be left open, because now the water going in the floor is cool not hot. I remember my friend had plumber install his kit, plumber told him to leave it open. My friend was confused and called Hydro smart and they told him to leave it open. He went through so much propane as the system was pretty much running 24/7. He decided to shut that purge valve close, and it was normal operation heating the home and not burning money.

Anyway now I do realize that this valve thing could have confused things, It's just that when I open it a little, the boiler runs better, but GPM goes down. I thought that information would be valuable.

 

[Shibby021]

Here is video of the boiler running

 

[Bannerman]

purge valve is supposed to be closed while filling up the system then it is to be left open during normal operation. That

Include some photos of this 'purge valve', or include a link to a product web page so we may better understand what you are using.

I was awaken by the smell of propane (my space is a 40x48 wide open bachelor pad)

Is the unit's combustion gas being exhausted into the building, not to the building exterior?

Is the propane gas pressure regulator(s) located within the building? Pressure regulators utilize a flexible diaphragm which has direct exposure to propane gas on one side, and is open to atmosphere on the other through an air vent. A defect with the diaphragm, will typically allow fuel to leak out from the regulator's air vent.

Should I add some antifreeze? I just don't like antifreeze has it reduces thermal efficiency

A closed loop hydronic system will typically be equipped with a chemical corrosion and scale inhibitor, and an oxygen scavenger, to reduce internal corrosion & scale formation, and to assist to eliminate dissolved oxygen. Perhaps the 'antifreeze' you are referring to is intended for those purposes, with an potential added benefit of lowering the freezing temperature of the water solution within the heating loop, should conditions arise for that to occur.

An antifreeze is often utilized for closed loop systems that are used for circulating both hot water during the heating season, and chilled water during the air conditioning season.

Raising temp to like 140 makes the unit shake violently, like little bombs going off inside there but rapidly in sine wave, and it starts to exhaust out of the unit which makes the room very stinky with propane exhaust.

Your video appears to show the burner is shutting off, and then is rapidly re-firing. This seems to be caused by a lack of fuel, which could be a result of a defective gas valve, a defective pressure regulator, or insufficient fuel vapor being delivered from the fuel tank, as Fitter30 was suggesting.

Propane is liquid fuel that must be vaporized into a gas before it is burned in an appliance such as your boiler.

Vaporization requires sufficient liquid fuel to be in direct contact with the tank's outer shell, so as to absorb sufficient heat from the exterior to cause the liquid to vaporize at a fast enough rate to satisfy the continuous vapor consumption requirements for the appliance.

While a propane tank may be capable of storing a substantial volume of liquid fuel, if the tank is not large enough to provide adequate surface area to vaporize enough fuel at a fast enough rate to at least meet the fuel consumption requirement for the appliance, there will often be combustion issues.

As the external temperature becomes colder, the rate of vaporization becomes reduced, so a propane tank that may satisfy the consumption requirements while exterior temperatures are moderate, may no longer satisfy vaporization requirements while exterior temperatures are colder.

A similar situation will apply as the amount of liquid becomes lower in the tank, as less liquid fuel will be in direct contact with the tank shell, thereby reducing the amount of heat absorbed from the exterior.

As a tankless boiler will typically consume gas initially at the burner's maximum firing rate, and will then modulate to a lower output as the water temperature increases, your propane tank will need to be large enough to continuously vaporize at least 120,000 BTUs of fuel, even while there is a low amount of fuel remaining during the night in the middle of winter when external temperatures will be typically lowest.

Although a vertical propane tank may have an identical fuel capacity as a horizontal tank, a horizontal tank will be usually capable of a higher vaporization rate, even with less fuel remaining since the remaining fuel will have larger surface contact area with the tank's outer shell.

 

[Shibby021]

Include some photos of this 'purge valve', or include a link to a product web page so we may better understand what you are using.

https://cdn.shopify.com/s/files/1/0728/3870/9530/files/Filling_Purging_System_122003.pdf?v=1706208318

Is the unit's combustion gas being exhausted into the building, not to the building exterior?

Is the propane gas pressure regulator(s) located within the building? Pressure regulators utilize a flexible diaphragm which has direct exposure to propane gas on one side, and is open to atmosphere on the other through an air vent. A defect with the diaphragm, will typically allow fuel to leak out from the regulator's air vent.

It's being exhausted outside

the appliance regulator is inside the building, 2nd stage is mounted on the house outside, 1st stage on the 500 gal horizonal tank.

Propane smell comes out of the boiler whenever I open the ball valve right below the boiler gas inlet.


The 500 gal tank is the main tank that I want to use but the boiler runs worse off that tank than when I switched to 100lbs vertical tank last night. The boiler was working perfectly fine few days ago before I disconnected it to get my well water line in then I put in the new gas line to the 500 gal tank's new location.

Both setup, 500 gal and 100lbs, worked fine in February at minus 15 degrees even when the 500 gal tank was below 15 percent, the 100lbs tank however was inside to keep it warm. the coldest it got here in the last few days was 30 degrees, by midday its 60-70. I do understand that propane loses performance at colder temperatures when tank gets low, but I'm not seeing why pointing at how it works is needed when there's plentiful propane here. I could get my empty 100gal tank filled up and try it, but I don't believe it's tank issue when I am getting enough pressure at the boiler? Are you suggesting that I could have a bad regulator? I do have a used appliance regulator that I can swap with the current appliance regulator and see if that makes difference.

I apologize in advance as I am bit confused why people are trying to explain to me how propane works.

 

[Fitter30]

https://cdn.shopify.com/s/files/1/0728/3870/9530/files/Filling_Purging_System_122003.pdf?v=1706208318

It's being exhausted outside

the appliance regulator is inside the building, 2nd stage is mounted on the house outside, 1st stage on the 500 gal horizonal tank.

Propane smell comes out of the boiler whenever I open the ball valve right below the boiler gas inlet.


The 500 gal tank is the main tank that I want to use but the boiler runs worse off that tank than when I switched to 100lbs vertical tank last night. The boiler was working perfectly fine few days ago before I disconnected it to get my well water line in then I put in the new gas line to the 500 gal tank's new location.

Both setup, 500 gal and 100lbs, worked fine in February at minus 15 degrees even when the 500 gal tank was below 15 percent, the 100lbs tank however was inside to keep it warm. the coldest it got here in the last few days was 30 degrees, by midday its 60-70. I do understand that propane loses performance at colder temperatures when tank gets low, but I'm not seeing why pointing at how it works is needed when there's plentiful propane here. I could get my empty 100gal tank filled up and try it, but I don't believe it's tank issue when I am getting enough pressure at the boiler? Are you suggesting that I could have a bad regulator? I do have a used appliance regulator that I can swap with the current appliance regulator and see if that makes difference.

I apologize in advance as I am bit confused why people are trying to explain to me how propane works.

500 gallon lp tank is large enough to supply the correct amount of vapor to the burner a 100 gallon can't.Lp is heavier than air it stays close to the ground. What your second stage regulator brand, model, office and pipe size? Might have to much secondary air. Did ever know about lp vapor pressure most people don't. Brand and model of boiler? Did you purge the line?

 

[Shibby021]

2nd stage is the blue one, it's 3/4" both ends and fittings are for 1/2" OD copper pipe to the house and also from the 1" propoly line from tank.

Red is 1st stage on tank, silver is appliance reg in the house.

 

[Fitter30]

Maxitrol should have a white spring 7-11"

 

[Shibby021]

Maxitrol should have a white spring 7-11"

I can't tell as the screw is blocking the view to it unlike the other 2.

 

[Reach4]

https://www.supplyhouse.com/Maxitrol-325-5L-3-4-3-4-Line-Regulator-600000-BTU

Maximum input pressure 2 psig.

Red regulator says 5-10 psig out. Five psi is more than 2 psi.

 

[Shibby021]

https://www.supplyhouse.com/Maxitrol-325-5L-3-4-3-4-Line-Regulator-600000-BTU

Maximum input pressure 2 psig.

Red regulator says 5-10 psig out. Five psi is more than 2 psi.

Red is on tank blue is on house. Blue outlet is 1 to 2.5 psi.

 

[Fitter30]

Red is on tank blue is on house. Blue outlet is 1 to 2.5 psi.

Red is at the tank, blue at the house and silver at the heater. Lp verses nat gas is a pain. There is a dine line for the correct setup. Lp can hum loudly, vibrant or burn like poop. Page 46. Item 112 air adjustment. Mark it with a pencil before moving it. Baby steps.

Resources & Literature

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www.google.com

 

[Shibby021]

I got in touch with the manufactuer on monday and they sent me info and we went back and forth on email, finally last night I went to Menards as that is where I bought the boiler. I asked them if I could exchange for new one, good thing it was still in warranty and they said I could do that. So I took it off and brought to them and picked up the new one, installed it same night, and oh boy it runs wonderfully now!

I am guessing something cracked in the previous boiler.

Most important thing is that I have heat now!

Thank you all for the help!