Lochinvar RBN180 noise

Pags

Hi there I am new here! I have a Lochinvar RBN180 Boiler about 12 years old. This noise just started , when it gets up to about 190 degrees it starts moaning. I tried flushing out the system but no changes. Sometimes the noise is louder then others. The unit makes my domestic hot water as well as 2 zones of heat through hydronic heat coil units connected to air handlers. The noise seems to be coming from the outlet side of the boiler I think? There are no leaks and all circulating pumps seem to be working fine. The unit continues to operate fine but the noise wakes me at night.

I was thinking of lowering the high limit by 5 degrees will this help or do I have another problem?

Thanks,

Mark

Steve Whitbeck

build up

There is a build up on the inside of the heat exchanger tubes. The only other cause could be low water flow.

Pags

Lochinvar RBN180 noise

How do I clean out the inside of the tubes?

Steve Whitbeck

copper heat exchanger cleaning

This is why I don't sell copper tube boilers.

The only proper way to clean the heat exchanger tubes is to remove the heat exchanger section and soak it in ACID - Not a homeowner project.

hot_rod

run a de-lime cleaner

through the boiler for a day or so. I have had good luck with Hercules Sizzle, or a product from Chemical Specalities in Denver, Inhibited acid/ mineral deposit remover.



Is it a DHW boiler or hydronic? If it is a hydronic it may have a leak in the system and it is taking on fresh water, and the minerals with it.



Determine if it is taking on fresh water, and clean it out ASAP, the longer it goes, the tougher to clean. In some cases the tubes need to be rodded out if the build up gets too thick on the tubes.



It's not the boilers fault that it has a mineral build up. Cast iron boilers will do the same thing if they get a lot of minerals or hard water running through them. So will your water heater

Steve Whitbeck

copper tube

Copper tube boilers just tend to do it a LOT sooner and tend to melt down.