Hot Dawg high altitude kit?

[enrare]

I live in Denver area at approx 5400 ft elevation and picked up a 4 year old natural gas Hot Dawg HD60 from Craigs List. Heater has standard factory "49" orfice jets and according to Modine literature these size jets are only recommended up to 2000 ft elevation. The inside of the power exhaust vent unit looks clean and not sooted up and same for the section of vent pipe that came with it. I called Modine and could never talk to a real person, just an automated referal to a local rep. I called the rep who really was more interested in refering a contracted HVAC guy come to my house and no doubt try and sell an install job. When I asked about purchasing the high alt kit I was told Modine will not sell parts to non-contractors. Rep did mention the Natural Gas company here does something to lower the BTU content of the natural gas to compensate for the altitude, but depending on what my gas line pressure is and "other" factors to be determined by a licensed contractor the high altitude kit may not be needed. Can anyone shed some light on this matter to help me figure out if I need to re-jet the heater

 

[frankush]

In the Hvac industry it's not uncommon for manufacturers or their vendors to restrict parts purchasing to contractors or other "qualified" individuals. I would call Modine again and try and speak with someone in technical support. Mention the fact that you can't seem to get a straight answer from different contractors. They should help you out.

 

[rponfick]

I am in the Denver area also and just went through this exercise. I have a new 80K Big Maxx natural gas unit. On my unit, the instructions for altitude adjustment only referred to lowering the gas operating pressure as altitude increases. I bought a manometer, which measures gas pressure, and lowered my operating pressure from 3.8" to 3.2" of water column.

I could be wrong, but I thought you changed the jet size only on the propane fired units.

Ralph

 

[enrare]

I have some lierature from Modine's site for the high altitude orfice kits and it lists kit item numbers for both natural gas and propane units for different elevation levels. I need to go back over the installation instructions again about the gas pressures. It mentions the inlet pressure to the heater must be 6-7" W.C. and if it is higher then a regulator needs to be added before the heater. There is also a little blurb on Main Burner adjustment and manifold pressure adjustment with a 12" high "U" tube shaped water manometer. Where did you get the manometer? Can it be used to also test the gas pressure going into the heater or is a different gauge needed to take that pressure reading?

I am in the Denver area also and just went through this exercise. I have a new 80K Big Maxx natural gas unit. On my unit, the instructions for altitude adjustment only referred to lowering the gas operating pressure as altitude increases. I bought a manometer, which measures gas pressure, and lowered my operating pressure from 3.8" to 3.2" of water column.

I could be wrong, but I thought you changed the jet size only on the propane fired units.

Ralph

 

[frankush]

I've got this one. It's simple and works well.

http://www.amazon.com/dp/B0016H12KS/?tag=atomicindus08-20

 

[cowboyjosh]

XCEL already derates natural gas for altitude, a little adjustment with a manometer and you should be ok. Sometimes REZNOR still wants the pressure switch changed for the altitude.

 

[enrare]

XCEL already derates natural gas for altitude, a little adjustment with a manometer and you should be ok. Sometimes REZNOR still wants the pressure switch changed for the altitude.

Thanks for the info on Xcel derating the natural gas. I assume that NO high altitude kit is necessary for the heater to run properly here in Denver? What would happen if the high altitude injectors where installed?

Is the adjustment you refer to the one made on the gas pressure regulator by connecting the manometer to the outlet pressure tap and then adjusting the main gas pressure regulator spring to achieve the proper manifold pressure? Which according to the install manual table should be 3.5" W.C., does this sound right?

 

[enrare]

I've got this one. It's simple and works well.

http://www.amazon.com/dp/B0016H12KS/?tag=atomicindus08-20

Noticed this gas pressure test kit has 0-35" W.C. scale. Since I'm working with natural gas would I be better served with model 78055 that has a 0-10" W.C. scale? Looks like maybe the 0-35" gauge might be more geared toward the higher pressure found in LP applications?

One other thing would you guys consider purchasing a lightly used gas pressure test kit from ebay to save a little $ or spring for a new one. I don't know about the chances of the calibation getting off on these and therefore a bad idea of buying a used one. I'm thinking for me this may one of those things that gets used once or maybe twice, but even if I spend $50 to $60 for a new one I'm sure it will be far cheaper than a service call from a HVAC contractor.

 

[rponfick]

I called Xcel when I was going through this about 2 months ago and the local technician said the gas is not adjusted for altitude. The overall BTU content is diluted with air if the gas well stream is to high and you need to get the household BTU down to burning temperature that does not melt your pots on the stove. He indicated that the average BTU varies depending upon where you live and the source of their gas.

I think the input gas pressure has to be adjusted with a regulator if the input pressure is too high, but I think this is rare. I adjusted my output pressure to abou 3.2 and the Xcel thought that was good.

I have the Yellow Jacket # 78055, used once, that I may be able to be talked out of.

Ralph

 

[enrare]

I called Xcel when I was going through this about 2 months ago and the local technician said the gas is not adjusted for altitude. The overall BTU content is diluted with air if the gas well stream is to high and you need to get the household BTU down to burning temperature that does not melt your pots on the stove. He indicated that the average BTU varies depending upon where you live and the source of their gas.

I think the input gas pressure has to be adjusted with a regulator if the input pressure is too high, but I think this is rare. I adjusted my output pressure to abou 3.2 and the Xcel thought that was good.

I have the Yellow Jacket # 78055, used once, that I may be able to be talked out of.

Ralph

sent you a PM

 

[enrare]

Sent you a few PM about the manometer, not sure if you got them. Let me know

 

[Inwywind]

Did all of the glowing go away at 3.2?

 

[rponfick]

No, the glow did not completely go away, and it is only visible in low light conditions. It is in the first joint as the heat exchanger curves back to the inside. I have seen other comments on the forum that they experience the glow also. Also, Mr. Heater's technician said it was normal and the heat exchanger is guaranteed for something like 10 years.

So, it is off my list of concerns keeping me awake at night.

Ralph.

 

[enrare]

Those that have installed your own heater and/or gas line what is your thought on pulling a permit with the city and getting them involved? I don't really want to do this but I have seen some comments regarding home owners insurance and being left S.O.L. if you happen to have a fire and the heater was not installed by a licensed professional and checked out by the city.