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Joined on February 3, 2007

Last Post on August 22, 2014

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@ December 18, 2012 3:12 PM in Dual Duct VAV boxes - Inlet Pressure

Contact your local Trane rep. ask for  literature and request a I.O.M. (manual)  also on yahoo look up   HVAC units-Varitrane dual duct boxes.   you will need some training on this one.   may need  Rover/comm 4 software and Rover tool


@ December 17, 2012 2:26 PM in furnace firing issue

You need a minimum of 5 inches water column to inlet of most gas valves and 3.5 inches to burner on most  furnaces,  these setting can change if you have a 2 stage valve and on commercial burners. most diaphram style gas valves depend on this 5inch to 3.5 inch pressure drop to operate correctly.


@ December 17, 2012 1:05 PM in furnace firing issue

Have  a licensed Hvac contractor check it.   could be low gas press. you could start with your gas co.   alot of them dont charge to check your furnace.

gas press.

@ December 15, 2012 6:23 PM in Honeywell random fault lockout

You need to maintain at least 6 inches w.c between the reg on the boiler and your parrallel regs.  while the burner is operating.  ( where the pilot piping is attached to the gas line )   7 inches would be better,  if you cant burner wont oper. properly.   have the Gas co. meet you at the job site

rule of thumb

@ December 15, 2012 5:29 PM in suppemental heat

400 cfm for cooling and 500 cfm for heat pumps is data used in Carrier ht pump and air balance manuals, as well as many other unit manufacts.   the other data came from SMACMA.   I agree a 10 degree temp rise is'nt much but some of the jobs I looked at in northern CA had no suppl. heat and barely had an electrical service to the bldg big enough to support 40 amps to each unit, so a 10 degree rise was better than nothing. I do know about all the stages needed in colder climates as i started my career in Denver in 1974 and also worked in SF for 20 yrs.


@ December 15, 2012 4:54 PM in Dual Duct VAV boxes - Inlet Pressure

Are they DDC boxes or pneumatic.   minumum static is critical, If you want vairiable air volume your boxes will need velocity controls, do they have a hot duct and cold duct run to them,  need a little more info.


@ December 14, 2012 10:39 AM in pumps

sold    Dan can you remove post      thanks


@ December 13, 2012 5:35 PM in Circulation pump vibration noise?

Get a tech to check for pump cavitation (air in system getting into pump )  beftore replacing pump.  this is what is called a maint. free pump, no coupler.  If the pump is within a year old  it should still be in warranty.


@ December 13, 2012 3:32 PM in One Pipe Steam System Flooding

Did they check fill valve ?


@ December 13, 2012 3:27 PM in Circulation pump vibration noise?

could be a loose or broken coupler if its a B&G series 100 pump or taco equivalent , or a bad motor or pump bearing,  it most probably will get worse.  Better have a pro look at it.  have the pump brand, mod, serial # and motor horse power  on hand when you call.

fill valve

@ December 12, 2012 6:32 PM in One Pipe Steam System Flooding

Not sure if you have checked the fill valve assy. closely.  Most Mcdonnel Miller LWCOs  have a replaceable valve that can get corroded and plugged up allowing inlet water to seep by the valve seat,  they can plug up within 3 months if you dont change or clean the strainer basket. I had a job where after 2 weeks the boiler would be flooded, found the sa-51-101-102 was corroded inside, I replaced the valve assy. on the no.51 LWCO.   no more flooding.   be careful with these valves as excessive water press. on valve inlet on start up can damage valve. also you should inspect the float assy. sometimes they can develope a hole or colapse.  I recommend completely going through LWCO (low water cut off ) annually.


@ December 12, 2012 11:53 AM in suppemental heat

I used 7.5 kw instead of 7.9 kw    formula stays the same    my mistake


@ December 12, 2012 11:48 AM in suppemental heat

the 10 degrees is the supply air temp. rise I would like to see during ht pump defrost mode considering the supply air temp. could be 50 deg.  actually 15 -20 degees would be better.  using formula for single phase, 3 phase will differ.  Amps = watts divided by volts   7.5 kw (7,500 watts ) divided by 208 volts =  36 amps, or a 40 amp service.     Let me Know what you think I dont want to give out wrong info
Thanks  Rick


@ December 11, 2012 5:50 PM in Commercial Boilers

 I agree, above 399mbh  considered commercial.  For a number of years now in San Francisco  any commercial boiler  400 mbh or higher can't be replaced with an atmospheric burner style boiler. It must have a power burner. This is to help with controlling flue gas emissions

suppemental heat

@ December 11, 2012 5:09 PM in suppemental heat

 Here are some formulas that are helpful in figuring out suppl. heat on air to air heat pumps.
KW required  when CFM and desired temp. rise are known  ( rule of thumb 1 ton = 400-500 cfm )     KW = CFM times T.R.(temp rise) divided by 3150.
Temp. rise = KW times 3150 divided by CFM
Amps = KW times 1000 divided by volts
example   A 5 ton heat pump would need a 7.9 KW heater for a 10 degree T.R. This would require a 40 amp service at 208 volts just for the supplemental heater.


@ December 11, 2012 3:58 PM in New Boiler - Hammering and Leaky Air Vents

I agree with all    also looks like header pipe size is reduced


@ December 11, 2012 11:09 AM in Adding a patio room zone

Taco/HVAC  on the internet has great resources , they use to have pex tubing flow/press. drop charts.  Taco makes a good pump you could use on your project.


@ December 10, 2012 11:48 AM in One-Pipe Steam-TRV or Better boiler controls?

A Danfoss RA-2000 1 pipe valve and a G-8023 operator together run about $100.00. I have used these in old multi story office bldgs. in San Fran. with some success.  The problem with this type of control is that the boiler must cycle alot and reach below 0 psig. on off cycle       Dan Foss has a 1983 memo explaining this.


@ December 9, 2012 10:40 AM in primary secondary schematic

on yahoo  look up Taco/HVAC


@ December 8, 2012 3:00 PM in Badly plugged sections

I agree I would get someone familiar with your boiler to determine how to clean it   I would also get someone with a strong background in boilers who  can do a complete flue inspection ( proper flue size, fresh air,combustion air ) and a combustion analysis of the burner.     I would also put a co monitor in the boiler room.  Be carefull using any chemicals in boiler rm.  especially if there is other gas or  oil fired room.


@ December 8, 2012 11:32 AM in T-stats in Apts...

White Rogers makes a commercial t-stat that allows you to install 3 remote  sensors, you can set priority on different sensors   sensors are sold seperate, this is a 24volt heating cooling t-stat, in your case dont wire up cooling. I used in a 3 story bldg, I was controlling 1 reznor M.A unit, I had the t-stat on top floor and had the keypad locked out, I set mine up to take an average of all floors as the controlling set point.  sorry dont know part #   check with controlco in San Fran.  415-647-9445.


@ December 7, 2012 11:21 AM in pumps

2-  grundfoss  UP-26-99BF bronze pumps   unused in boxes less than 2 yrs old    make offer     in the Sacramento CA area
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