Ignition cables getting Cooked....Boilerpro

Jim Davis_3

I used to sell hundreds of these boilers in the 80's & 90's and this was a common problem. Normally when the boiler was venting properly the O2 readings was excessive 10%+. But when venting was an issue the O2 was low 6%-. Several fixes. Found that the heat from the burners was not reach the rear of the burner. Started raising the rear of the boiler 1" and this took a lot of heat from the front and in some cases improved the venting. However there were too many cases where the chimney was pulling all the draft through the drafthood and little or nothing through the unit. Lochinvar is the only manufacturer to date that has given me a letter saying it was okay to modify their boilers in the field. These modifications were only allowed by those who had the proper test equipment(combustion analyzer) and proper training. Found these boilers to operate perfectly with minimum wear and tear and were saving my customers 15-20% over conventional cast iron equipment.

Boilerpro_5

Sturdier alternatives?

I have 3 Lochinvar RBN-270 Boilers installed in a staged heating plant for a church and the standard ignition cables are getting cooked in short order. I replaced the first set after only 4 heating seasons...Spark plug boot and cables were dried out. I was back again yesterday and after 2 heating seasons the boots are already dried out. I have always noticed there seems to be an intense amount of radiant heat coming from this boiler line when you are near the burners when firing. I beleive I have seen cables with ceramic ends and a shielded wire, but I don't know where to find them. Any other ideas?

Boilerpro

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ScottMP

I would contact

Lochinvar. Many times manufactures find alternatives when there is a problem in the field. They may tell you that your the only one, but we do have a retro-fit kit at no charge

Start with them. Sounds like there should have been a shiled installed ?

Scott

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Ike Gatlin

hmmmm...

First my guess is that these units are older because if it was getting that hot underneath, the spill/roll out switch should be going off.
I would also say that if you are generating that much heat, that you may want to look at two things... First, soot or a build up on the heat exchanger fins. This doesn’t allow the hot gases to flow through the unit. Second, I would look to the vent. Check the draft. About 18" off the top of the appliance. The draft should be in the .03-.05 negative range.

Ike Gatlin

Unknown

I used to have

I used to have that problems, with no help from the reps. So I switched over and only order with standing pilot. Pilot costs is mimnal compared to money spent on replacement...

Charles G.

Ignition cables

Ditto what Ike said. Could be poor drafting through unit(s). Another possibility is installation--are these units up on blocks? Should they be? Check for over-fire condition/gas pressure. Mechanical room conditions--fresh air/exhaust fans. If all is as it should be, maybe just replace the cables during yearly P&M check-ups.

bobbyg_2

I too had two contractors who had the same issue. In the end the rep suggested we take out one or two (in the middle) heat exchanger v-baffle(s) to allow the heat to escape up and out.

The venting was within the .03-.05, gas pressure o.k., units were on blocks. You could feel the heat radiating. I was told, "I'm the only one with this problem and the line is being updated anyway".

I totally disagreed, it was for a water heater, 1.flow rates are critical but they are set by delta t 2. efficiency must be affected, (delta t/flow rate relationship changed)

Both contractors took one v-baffle out just to stop the callbacks, and one walked away unsatisfied with the support (vowing to never buy one again.

These were on the pre-solution boiler era units. It was only on the largest sizes with 5/8" ID tubing heat exchangers (RWN3??)

joel_19

heat

I would also take a very serious look at the possability of backdrafting Via exhaust fans in the place. Close all outside doors and windows crank them on and see what happens. note PAV's (power Attic ventilators) can be big culprits in that kind of problem and people forget they are up there and only concentrate on the obvious stuff , but a PAV may be 1400CFM or more and that air might not be coming into the attic via the soffit vents.

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Boilerpro_5

If I remember..

you're a Lochinavar Rep. Actually, I've found that the high amount of radiation is present on all of these series of boilers that I installed, even when brand new. 2 years ago I completely dismantled and cleaned the fins and yesterday I blew them out from beneath to clear most of that lightweight greenish debris that collects on the fins. I did run a combustion check on these and the O2 is quite low, with elevated levels of CO, and low stack temps with the boilers up to temp. Low O2 seems to be typical on these boilers.....they seem to be set up with very tight O2 levels like I've seen in many older atmospherics. Improves efficiency, but can get you into trouble if everything is not quite right. The boilers have return temp protection set at 130F and with a minimum supply temp of 160F. I previously had the return temp set lower, but was seeing evidence of condensation the first several inches of the return side of the heat exchanger. That corrosion was cleaned out 2 years ago. Boilers are set on a flat concrete foundation. I also typically use standing Pilot, but these units are only available electronic ign., which I never have liked.

Like others, very poor factory support has sent me elsewhere for boilers.

Boilerpro

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Ike Gatlin

yes I am...

BoilerPro-
I have known this product from its inception to its redesign.

Yes, I agree the old style MF boilers had what seemed to be a good deal of heat spilling from the front. This is monitored by the ANSI required spill and rollout switch located in the front of the unit. These switches are set to break at 210 degrees. They are manual reset. The ignition cable is a silicone based insulator rated at 210 c. Now that is a lot of temperature.

At one time, we used a simple push on connector from the cable to the pilot. That was about 1989. I recall heat issues with those. We then switched to a RAJA connector. The RAJA is a solid nickel plated connector designed specifically for the Honeywell pilots. If you want I can make a raid through the plant and send you a few.

I personally have never told anyone to remove v-baffles from an appliance to "fix" anything.

Ike

Unknown

Boilerpro you say the boilers

are on flat concrete foundation, is it a full coverage of the entire bottom of the boiler and extending out a couple of inches all around?

What kind of draft hood does it have? What is the venting arrangement? If you want give me a call or I also will be in the chat room tonight at HVACTV.com at 8:00 PM, I am usually in the chat at around 7:45 PM EST we could chat about this unit.

bobbyg_2

No sir, I am referring to my representative. I never spoke with anyone else from the factory, except my representative and his regional sales manager (He is the one who said, "We aren't going to look into this because we are going through a redesign")

bobbyg_2

Ike, after reading my last response I want to add that you have been very helpful with any questions I have had.

I only wish I knew you before this issue came up. I certainly would have asked you.

Thank you.

Boilerpro_5

A little more info

I have one of the cables on my desk and the boot is very dried out in the direction facing the burners, but the side away from the burners is just fine. It does not appear to be an air temp issue, but a radiant heat issue, when considering this and the fact that the spill switch has not tripped. In fact I have never had a spill switch trip on these units, except when we were first testing the staging control and safties and short cycled the burners.
Its great to have someone responsive from Lochinvar, like you. My experience, as with others in my area, had been very poor in the past.
I'll take you up on you offer for the parts. WE have 3 of these boilers installed at the location. All the others are standing pilot models topping out at 135,000 input, which we inially had problems with, but Tim M helped me solve these.

O
Boilerpro

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Ike Gatlin

Parts on the way.

> I have one of the cables on my desk and the boot

> is very dried out in the direction facing the

> burners, but the side away from the burners is

> just fine. It does not appear to be an air temp

> issue, but a radiant heat issue, when considering

> this and the fact that the spill switch has not

> tripped. In fact I have never had a spill switch

> trip on these units, except when we were first

> testing the staging control and safties and short

> cycled the burners. Its great to have someone

> responsive from Lochinvar, like you. My

> experience, as with others in my area, had been

> very poor in the past. I'll take you up on you

> offer for the parts. WE have 3 of these boilers

> installed at the location. All the others are

> standing pilot models topping out at 135,000

> input, which we inially had problems with, but

> Tim M helped me solve

> these.

>

> O Boilerpro

>

> _A

> HREF="http://www.heatinghelp.com/getListed.cfm?id=

> 393&Step=30"_To Learn More About This

> Professional, Click Here to Visit Their Ad in

> "Find A Professional"_/A_

Ike Gatlin

parts on the way

BoilerPro-
I am on my way out the door to SC. I will be there all day. I get back in the office Thursday. I will make my parts raid for you then.

Ike Gatlin

Boilerpro_5

THANKS!

> BoilerPro- I am on my way out the door to SC. I

> will be there all day. I get back in the office

> Thursday. I will make my parts raid for you

> then.

>

> Ike Gatlin





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Boilerpro_5

THANKS FOR YOUR HELP!.....nm



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Unknown

Ike,

what would the normal combustion analysis be on these boilers? Radiant energy as Boilerpro describes seems to me to be a combustion issue developing very high temps in excess of design capabilites of ignition cables. I would be concerned about the possibility of a drafting issue. This would be high or excessive draft above the draft hood and poor or no draft below the draft hood. From the pictures it appears those units have the draft hood built in to the boilers.

I am also concerned about the what appear to be Effikal dampers on the units.

hr

Wrap 'em

with some of that muffler "band aid" heat material If in fact everything is to spec and it keeps occuring.

Just kidding. Sort of.

hot rod

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Boilerpro_5

They are Effikal dampers...

and factory equipment. Draft readings were not particularly high at the vent inlet or above the heat exchanger....but they were done with the analyzer, which I understand is usually not the most accurate. Plenty of rise above the boilers, but is is also pretty warm here, so draft is not at strong as in the winter.

Boilerpro

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Unknown

Hot Rod you are

not to far off. I have in the past made a heat shield from sheet metal to protect cables from high temperature problems. Attached it to the pilot and then slipped the cable up into place for good ignition.

Boilerpro_5

Sounds like you and Tim M are pointing me in the same direction

A possible venting issue, which seems to agree with my combustion readings. I'll E-mail Ike further on this. If you could E mail me with the modifications made for the venting, I'd appreciate it.
Thanks guys!


Boilerpro

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