lochinvar problems

Jonathan Smith

In the past about 5 years ago we installed quite a few lochinvar copper tube boilers. (what a misteak) at least 1/2 of these boilers have a sooting problem. It starts with a green substance in the heat exchanger on the copper tubes. Then as this builds up it starts to build black soot.
We have checked adjusted and made sure we have proper gas pressure, Flue draft, supply and return temperatures. Im going crazy trying to get these boilers to operate properly. Has any one seen this problem and how have you dealt with it. Jon Effective air Glenview Il

hr

What are they inhaling?

Hard to believe they could all be installed in a space that has soaps of chemicals stored by?

I've been told that the normal byproducts of burning natural gas will attack the thin copper fins after awhile. That green color seems very common on all copper tubes I have cleaned or worked on. Not sure what is being blended in natural gas these days as a filler could be the blend is more corrosive to copper?

Short cycling really brings them down. It's very easy to build a short cycling system with a low mass, low water content boiler like that. Multiple and sometimes micro zoning will be very hard on them. They work great, and efficiently under constant load, but you start switching them off and on a few times a minute and that soot problem could arise. They need to shut down dry, both the hx and entire flue run or they will condense, drip, and start problems.

I prefer to see them installed PS with a buffer tank when used on zoned systems.

Sounds like two step gas valves are coming back on all the sizes. The older modulating gas valves used on some Raypack models were a fairly good solution to the short cycles also.

You really need to watch them for a few hours under various load conditions to get a handle on what is going on. perhaps a data logger would give you insight into what is going on when you are not there. Be interesting to get a weeks worth of burner on/ burner off time periods.

hot rod

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

marc

low temp

are you running them below 140, if so you need to have the low temp. bypass piping on them, they will condense and start to plug up, marc