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Thermoflo gas valve

DrFarquad
DrFarquad Member Posts: 4
in Gas Heating
New member here! 

I have a thermoflo boiler (gwi - 095-l-t) that recently got flooded. Luckily only the main gas valve was the only thing effected. 

Called the local plumbing supply store who deals with thermflo boilers, they got in contact with honeywell and got me their "universal" replacement valve. (Vr8245m2530)  originally my boiler has vr8204m2701 valve. 

Main difference I'm seeing is that pressure ratings. The 8245 has a rating of 3 - 6 IWC, my original valve has a rating of 8-12. Boiler calls for 11iwc. 

With the new valve installed and the correct springs installed for propane, obviously I can only get 6iwc out of it. Hopefully I am right about this but I'm believing that I had gotten the incorrect valve. Boiler seems to be running about normal. Maybe the pilot light is a little low, but I never really paid attention to how it originally was. Looks to me it needs to be bigger to fully cover the flame sensor. 

Before I call the plumbing store back I was hoping to get some more insight on this. I can take some more pictures of it all if anyone needs some. 

Thanks Bob. 

Comments

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,517
    Most all propane boilers are 11" wc measured on the outlet side of the valve when the burner is on.

    But you should really have someone with a combustion analyzer check this out when you are done. The pilot and the burners should be removed and cleaned and all safety controls checked
    mattmia2
  • mattmia2
    mattmia2 Member Posts: 9,632
    Sounds like that is the valve for NG rather than propane. But once the vale is replaced, someone with a combustion analyzer needs to adjust it and the burner.
  • DrFarquad
    DrFarquad Member Posts: 4
    So no matter what I need to get someone in here to look at it? 
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,517
    @DrFarquad

    I think that is your best option.
    DrFarquad
  • mattmia2
    mattmia2 Member Posts: 9,632
    Make sure they are someone that knows how to use it.
    DrFarquad
  • DrFarquad
    DrFarquad Member Posts: 4
    Just talked with the local plumbing supply, guy is going to call honeywell tomorrow to verify its ok to give my boiler 3.5 iwc. He's telling me it'll still give me the correct amount of btu needed for the boiler. Said the valve is rated up to 135k. I asked him to verify with the lower pressure that I don't need to change anything else. Something just doesn't seem right with how I have this new valve.  After I get this sorted I'll be calling a boiler guy to come give it a look over.
  • mattmia2
    mattmia2 Member Posts: 9,632
    The combination of the pressure supplied by the regulator in the gas valve to the manifold and the size of the orifices sets the firing rate of the appliance. If the orifices are sized for 11" wc of propane then it will be severely underfired at 3.5" wc. Underfiring by more than a bit will mean there will not be enough heat for it to draft properly and you will get condensation in places like the heat exchanger and the vent system.
    DrFarquad
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,830
    DrFarquad said:

    Just talked with the local plumbing supply, guy is going to call honeywell tomorrow to verify its ok to give my boiler 3.5 iwc. He's telling me it'll still give me the correct amount of btu needed for the boiler. Said the valve is rated up to 135k. I asked him to verify with the lower pressure that I don't need to change anything else. Something just doesn't seem right with how I have this new valve.  After I get this sorted I'll be calling a boiler guy to come give it a look over.

    I have a feeling that you are operating with propane gas. There is a difference between propane gas (sometimes called LP Gas) and natural gas (sometimes called City Gas). Is your gas delivered to a tank on the property? Is your gas coming from a pipe that is connected to a gas meter? The type of gas you are burning will determine what pressure the gas valve should deliver to the burner. If you are not sure then, What is the name of the entity that you pay your gas bill to?
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • DrFarquad
    DrFarquad Member Posts: 4
    edited September 2021
    Ed, it's propane. Thanks for the input.

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