Joined on December 7, 2011
Last Post on March 21, 2013
@ March 21, 2013 12:37 AM in Maintenance techIf the units run via a EMS system such as Novar, you may have multiple units sharing the same address, or a unit left in Tranes test mode.
@ March 21, 2013 12:27 AM in adjusting the air on a power flame gas burnerYou have to adjust both the linkages, and the air shutter.
The position of the linkange on the crank arm at the firing rate motor effects the rate at which the air shutter opens in relation to the butterfly valve on the gas train. And the linkage adjustment sets the starting point for the damper.
Here is my process, regardless of make or manufacture, as they all essentially work the same. (By the way, I do this day in, day out roughly 6 months a year.)
Before starting the burner, lubricate the air shutter, and be sure it will not bind.
Step one: Run the unit in high fire, and set the max firing rate to that listed on the appliance. This is done by clocking the gas meter for a minute, counting rotations in that time, then doing the math for one hour. 1050 btu per cubic foot is a general guideline, but the heat content will vary based on the fuel in your area. Manifold gas pressure is virtually irrelevent in a power burner, regardless of what that manual says. On large boilers, it is essential to aquire the actual heat content of a cubic foot of gas from the gas supplier.
Step 2 : Put the burner in manual firing rate mode and divide the potentiometer into 10 or so segments.
Step 3 : Mark all linkange and drive arm positions for reference, then drive the motor to minimum position, and tweak the air settings until clean smooth reliable ignition and quality stack readings are met.
Step 4 : drive firing rate motor to the next segment and see what the results in the stack are, tweak position on the crank arm until clean combustion is achieved, then go back to minimum and see if its still good, repeat process all the way to high fire.
The general idea is to get the O2 readings as low as possible w/o producing excessive CO.
A reasonable target would be 4% O2 10% CO2, and below 50 ppm CO ( air free)
This process can take anywhere from an hour to all day. Some burners are more finicky then others. Do not rush this process, come back on a second day if need be. I've had some burners take me a week to tune in just right.
@ November 14, 2012 9:30 PM in Noisy induced draft boilerHas the noise level changed recently, or has it always been the same
@ April 22, 2012 4:42 PM in commercial univents with pneumatic tt'sI could write a book on pneumatic controls. What exactly do you want to know.
What brand controls?
Model #'s would be nice too.
what do you mean by tt's? Thermostats?
@ April 22, 2012 4:39 PM in PRV blues.....This may be another case of a problem with the spirovent.
I remember a few weeks ago, someone posted about a relief valve mysteriously going off when the piping was more or less correct.
I'd remove the exp tank, and take a good look inside the connection at the spirovent.
@ April 19, 2012 7:41 PM in flushing evap. coilTell the customer to bite the bullet and buy the new evap coil as well.
You have a reputation to build and maintain. Short cuts won't help.
@ April 15, 2012 4:55 PM in Buried copper piping leaksTry to find a way to reroute piping over head/above the concrete some how. maybe a soffit. Connections underground are always going to go bad eventually.
@ April 14, 2012 3:58 PM in Buffer Tank ASMEIn general though, when the tank is direct fired and over 200,000 btu
@ April 14, 2012 11:27 AM in Not always mod/conFulton, Paterson Kelley, Lochinvaar, Cleaver Brooks
To name a few of the bigger players
@ April 12, 2012 9:05 PM in CSD-1 CodeASME Standard CSD-1
The state of Mass may be more strict. But here is portion of CSD-1 that applies
burners between 400,000 and 2.5 million btu
For Power or mechanical draft burners You need:
On direct fired you need high and low gas psi safeties
on pilot fired you don't
You need two automatic gas valves in series (with a vent valve between) or one valve that has a proof of closure interlock switch.
Also, proof of combustion air is required.
For atmospheric draft, no pressure safeties are needed, and only 1 automatic gas valve is required.
In either case, 5 sec main valve closing time required.
You are also required to have both an operating temperature limit, and a manual reset high limit.
You are also required to have a LWCO, 2 main line manual gas shut off valves (1 before the regulator, and another between the final gas valve and the burner)
If the boiler is modular, with 2 separate combustion chambers below 400,000 btu, then
no gas psi safeties are needed in any case, and only one manual shut off is needed.
@ April 10, 2012 8:43 PM in warranty compressor replacementThey've all gotten there primary business functions away from resi.
Around me, in Chicago everybody's got a guy for this or that.
But, for that 5 million btu burner, ddc controller, frequency drive, etc... they don't got a guy.
That's the way I've gone, into the more specialized markets. Don't get me wrong, I like resi work. It's generally simple and strait forward, but it's hard to compete with dishonest hacks. The trouble is, many of the hacks know the business and advertising part of HVAC really well.
Put a few patches on a button down shirt, fancy letters on the truck, wear shoe covers, but look at the ac unit to see why it broke, what for? Hell, they'll even send a really nice salesman out to sell them 5 tons on a 1.5 ton load house. Ask this company how long the lead tech has been there, and find out he's 3 months out of some unknown churn em out tech school.
It drives me nuts. For most people short term cost is all that matters.
People seem to think that buying an hvac system is just like buying a car, but we know it's not.
@ April 8, 2012 10:48 PM in Direct Digital ControlsThere are a million different DDC control makes.
But, you have what you have. Unless the schools is willing to spends hundreds of thousands of dollars to update, then you are stuck.
Unlike the good old days, the controls of today are mostly proprietary. If you want to update, you'd need a new controller for just about every VAV, RTU, Air Handler, and Fan coil you've got.
It's not as easy as just uploading a new control provider, all the hardware has to be updated also.
@ April 8, 2012 10:42 PM in Happening elsewhere?25 to 1 turn down. That is awesome.
Have not been to impressed with Lochinvaar in the past, but I will certainly keep them in mind.
@ April 8, 2012 11:03 AM in Happening elsewhere?How is this different then any other indirect dhw? More heat exchanger?
@ April 6, 2012 4:29 PM in Redesigned steam piping...that the riser can handle both of them.
It might have been ok with just the replacement rad.
You'd need to run a dedicated feed from the main to the attic for that one to work.
Also you will need to calculated the EDR capacity of the all the radiators and make sure the boiler can handle what you need, then if so, calculate the size of the steam riser, and the run out to the riser to see if that will handle the radiator connected.
If you don't have it, order "the lost art of steam heating"
@ April 6, 2012 4:22 PM in Happening elsewhere?with mod cons is sizing. An oversized boiler will destroy itself, and that is where the majority of problems are born.
The other issue as far as quoting goes is that the extra cost does not stop at the boiler itself.
Especially on big btu projects, a boiler having it's own pump is a huge extra. I don't have the exact #'s but if you need to move 150 gpm at 20 to 50 head through a boiler, that does not make for a inexpensive pump. Then multiply that by the # of boilers, then add in the cost of adding electric service to a panel that is maxed out, etc.
That was what lost me that project, boiler pumps.
Mark could you please explain reverse DHW?
@ April 1, 2012 6:19 PM in Boiler making loud noise when filling storage tankHave the installing contractor come back out. Most guys will have no problem coming back out to make system adjustments.
Do you have adequate hot water in the shower?
Could be a pump mismatch, improper boiler or pump setting, or as simple as air still in the piping. Likely a flow problem.
@ April 1, 2012 6:08 PM in High efficiency gas boiler installationOnly issue comes at the set up of the controls. Each make is a little different, but with some due diligence and time reading manuals, anyone can do the set up.
Piping is virtually the same from one make to the next.
The real key is proper sizing of the boiler to the heat load of the structure, and not over sizing for any reason. Otherwise, you will have a basket case on your hands.
@ April 1, 2012 6:04 PM in Happening elsewhere?In commercial muli-family applications I like to leave the systems isolated from one another for redundancy. Nothing worse than having no heat or hot water in that kind of application.