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Honeywell pressure reducer question

kensheets2
kensheets2 Member Posts: 36
edited March 2021 in Radiant Heating
Hello 
I put my water makeup loop together but I come to understand the valve I purchased has a fast fill function.  Is my loop going to have any negative effect on normal operation?
The instructions to adjust pressure under "operation",  state to simply loosen screw and adjust scale, but directly below it states a 9 step process to adjust output pressure.  What is the difference?.
Lastly the reducer is factory set at 15 and the tank is 12.  Would that difference be acceptable?

Thanks

Comments

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,713
    edited March 2021
    I have a feeling that you purchased a more expensive valve than required for the task. That's ok, Overkill can be a good thing (sometimes). You can use 15 psi on a 12 psi tank pressure. Most will recommend that you either increase the tank pressure to 15 or lower the PRV pressure to 12. But it may not make that much difference to your system. It all depends on the amount of water in the system and the difference between the normal Cold temperature and the normal high temperature of your system.

    Your pipe fitting work looks great. Excellent craftsmanship. It is difficult to tell if you are using some type of shutoff valve at the air-separator/expansion tank connection because the boiler drain valve is blocking the view. (Red Arrow) If you are then that is great. If not I would have placed a ball valve between the boiler water pressure and the PRV (as illustrated) so you don't need to drain the boiler pressure off to service the PRV.

    The instructions say you can adjust under operation conditions OR use steps 1 thru 9. I believe you will be just fine.

    Yours Truly,
    Mr.Ed
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • kensheets2
    kensheets2 Member Posts: 36
    Thanks Ed
    10 CI rads on the system split into 2 zones each with own pump, i havent fired it up yet and very anxious to know what the return temp will be.  I'll probably pump up the tank, sounds easier than adjusting the valve.  As u can see I have a little work left.

  • kensheets2
    kensheets2 Member Posts: 36
    Mr Ed
    Ok makes sense and thanks for the compliment

    Ken

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,713
    It looks like there is an expansion tank fitting/valve from this angle. You already have the valve I mentioned, so you don't need the valve I mentioned. You already have it covered.

    Is your piping large enough to carry the total boiler capacity to the radiator on the coldest days? 1" copper will handle 80,000 BTU. Depending on the total EDR of the radiators and/or the total OUTPUT of the boiler, you may be fine, If you require more than 80,000 BTU, then the shared piping should be 1-1/4" That will allow up to 140,000 BTU thru. Your system will only be as powerful as the weakest link. A 200,000 BTU boiler connected to 300,000 BTU of radiators connected with 1/2" copper piping will only allow 15,000 BTU of heat into the building!

    You may want to look at this text booklet for a basic understanding of your system.

    http://media.blueridgecompany.com/documents/ZoningMadeEasy.pdf

    This is my go-to text for making sure a system will perform properly when needed. When the temperature outside is above "design temperature" you will not have any problem maintaining a comfortable home. Only when the temperature outside reaches the extremes will the maximum performance be needed.

    Respectfully submitted,
    Mr.Ed
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • HomerJSmith
    HomerJSmith Member Posts: 2,425
    edited March 2021
    Holy Cow, that's some expansion tank. How much water is in your system?

    With a tank that big, the tank's acceptance capacity is very large. 3 psi would make no difference.

    Basically, 15 psi water from the valve would push into the tank until the tank pressure is at 15 psi which would shut down the pressure fill valve's water supply.
  • kensheets2
    kensheets2 Member Posts: 36
    edited March 2021
    Hello
    My system is about putting out approx 80k BTU so I went with the 1" copper, this is a 100k boiler.  The selection guide for expansion tanks suggested the larger size when, I think it said 50k btu, using cast iron rads.

    Ken