Froling S3/FHG Cleaning


Minister of Fire
Dec 29, 2016
Guys, I just did a complete cleaning of my FHG before peak season arrives. My boiler had 430 heating hours on it.

I swept the chimney even though it didnt look like it needed it (only got a cup of ash, no creosote at all).

I took out the tubulators and brushed the tubes.

I brushed and cleaned around the combustion chamber and removed the ash under the tubulators.

I pulled some side pannels in the firebox and checked the primary air intake it clean.

I cleaned the firebox floor, pulled the cast iron grates and cleaned the ash from the secondary air inlet.

The question I have is, what's the easiest way to clean the area under the cast iron?
There is a small bolt head above the secondary air inlet and it was painful to clean with a small flat piece of wood. What advice do you Froling owners have for cleaning this area? Old paint brush maybe?

Yes, I covered the firebox floor with ash before I fired the boiler. I used all the ash from under the tubulators and spread it on the firebox floor. I typically maintain a 1" solid base of ash on the firebox floor, never scrape it clean. For a while I was scooping out the combustor daily but re-read the maintenance instructions and began leaving a layer of ash in the combustor also.
Last edited:

Beagle Dad

Sep 17, 2014
Ottawa Ontario
I clean the area below the below the cast iron twice a year using a shop vac. The only dirt is the ash that falls down from cleaning the bulk to the ashes out of the boiler.
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Minister of Fire
Oct 15, 2009
The manual I got with my Froling said not to use a vacuum on the refractory. Apparently it can cause wear.


Minister of Fire
Dec 29, 2016
I clean my fire tubes every 2 weeks ,it seems to make quite a difference on the flue temps . I also vacuum out the ashes from the ash access and in beside the refractory sides.
I have been brushing my fire tubes every 4 weeks as well as cleaning below them and brushing the narrow area around the lower refractory that leads back to the fire tubes. I scoop out the cylinder refractory every week but leave a heavy layer of ash in it so the flame isnt impinging directly on it. The floor of the firebox is also completely covered with 1-2" of ash. I use my poker to keep the space below the plates on the inside of the firebox clear of ash.