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Manual to Millivolt Gas Valve Conversion

Irontom
Irontom Member Posts: 18
I have an older 25,000 btu wall heater with a hydraulic Robertshaw gas valve (7000SRLC, built in thermostat) and want to know if it's possible to replace it with a millivolt valve so I can control the heater via a programmable thermostat. Any suggestions on a good replacement part number (710-502?)

Thanks,
Rick

Comments

  • Irontom
    Irontom Member Posts: 18


    I have an older 25,000 btu wall heater with a hydraulic Robertshaw gas valve (7000SRLC, built in thermostat) and want to know if it's possible to replace it with a millivolt valve so I can control the heater via a programmable thermostat. Any suggestions on a good replacement part number (710-502?)

    Thanks,
    Rick
  • The Robertshaw valve

    710-502 will be a good choice. It is small and compact and made for space heater application. You will have to find a pilot that will accept a 750 millivolt pilot generator. Does your wall heater have a limit disc? If so be sure and wire it in with the vlave. Now you have to find a programmable that works with millivolts. I am not sure if Robertshaw has one but I know Honeywell does but the part number slips my mind right now. Check with Bill from Honeywell who posts here and I am sure he will find you one.
  • Mitch_4
    Mitch_4 Member Posts: 955
    In Canada..

    You need to have it field approved by the local "authority having jurisdiction" as you are converting it fromitds original "Certified" design.
    You are basically making your own furnace. As such, without the inspection, and approval copied toyour insurance company, if you heater causes damage to the property, they don't have to pay as your appliance which will now NOT conform to any acceptable design standards or certification guidelines.

    Like filing a claim if you pile logs in a steel drum, and make your own vent system for a chimney in your living room,light a fire, and the place burns down, and you submit a claim.

    If you do this armour plate your behind, get it inspected, and approved and copy the paperwork to your insurance company.
  • Here in the USA

    it will have to go through a testing agency to be approved. The cost of that is usually around $35,000 per model. There are ways to do this without getting into complications. If you want to get technical when you change a thermocouple from one brand on a unit to someone elses brand you are changing the design and the equipment would have to be tested. I have been changing systems and retrofitting systems for years, my insurance company is aware of what I do and do not have a problem based on my qualifications.

    This should not be interpretd as carte blanch for everyone to just start changing things you had better know what you are doing and test everything when you are done.

    What do you do when a part is obsolete and no longer available, you come up with a replacement or replace the entire piece of equipment. The "News" had an excellent piece about this a while back from Tom Jackson a lawyer that they presented this very question to as to liability.
    I have a copy of his answer if anyone needs it.
  • John Starcher_4
    John Starcher_4 Member Posts: 794
    Tim......

    ....I'd sure like to see that!

    Starch
  • Mitch_4
    Mitch_4 Member Posts: 955
    For example

    What I was saying is that if parts are obsolete, and you are changing the operator, the replacement must function to the parameters of the original. Replaceing a W-R tcpl with a honeywell, no biggie, blower HP upgrade to move air, again no prob.

    What I wanted him to be aware of is changing the control system from one type to another should be inspected to make sure of its safety. In Ontario here in Canada, TSSA can field approve a change like this for about 135.00/hr. Having an independant authority testing and approving a complete control system conversion, as safe covers his behind. There are different requirements as to how the safeties should be wired in a millivolt application that differ from a 24v or other. ( as mentioned in a previous post).

    From the original post, he is changing a hydrolic ( no electrical or limits) to a millivolt system.) Probably not a problem as the unit is designed to run without a blower more than likely. But he should still have it checked. It sounds like a DIY and not a pro.

    The certification you speak of applies here too. But is required only if you plan on manufacturing/ mass producing the product. I too convert systems, and my insurance is ok with it so long as it gets reviewed and the HO insurance has a copy of the approval.

    If you can link the articvle, I would be intersted in it too.

    Mitch
  • Mitch_4
    Mitch_4 Member Posts: 955
    For example

    What I was saying is that if parts are obsolete, and you are changing the operator, the replacement must function to the parameters of the original. Replaceing a W-R tcpl with a honeywell, no biggie, blower HP upgrade to move air, again no prob.

    What I wanted him to be aware of is changing the control system from one type to another should be inspected to make sure of its safety. In Ontario here in Canada, TSSA can field approve a change like this for about 135.00/hr. Having an independant authority testing and approving a complete control system conversion, as safe covers his behind. As you are no doubt aware, there are different requirements as to how the safeties should be wired in a millivolt application that differ from a 24v or other. ( as you mentioned in a previous post to check).

    From the original post, he is changing a hydrolic ( no electrical or limits) to a millivolt system.) Probably not a problem as the unit is designed to run without a blower more than likely. But he should still have it checked. It sounds like a DIY and not a pro.

    The certification you speak of applies here too. But is required only if you plan on manufacturing/ mass producing the product. I too convert systems, and my insurance is ok with it so long as it gets reviewed and the HO insurance has a copy of the approval.

    If you can link the article, I would be intersted in it too.

    Mitch
  • Mitch e-mail me

    your postal address and I will send you a copy. My e-mail is [email protected]

    By the way there is no testing agency here in the USA that would do what you have in Canada. You guys up there have much better code standards and enforcemnt than we do down here in the USA. I would love to have someone to be able to inspect some of my work and provide protection based on testing and approval. The closest we come to this is a plumbing or mechanical inspector.
This discussion has been closed.