Cleaning The Flue Gas Box; Chemical Sweeping - Potterton NXR3i Installation And Service Manual

7.3.4

Cleaning the flue gas box

7.3.5

Chemical sweeping

General principle
Boilers are traidtionally swept mechanically. There are now chemical
sweeping methods which facilitate this maintenance work.
A chemical reagent is applied to the boiler's heating surfaces.
After application, the reaction is completed by igniting the burner. The
initial deposits are neutralised and pyrolised. The remaining
pulverent residues are easy to remove by sweeping or vacuum
cleaning.
The products
The product must be suitable for boilers with a cast iron body. Various
manufacturers offer products in the form of a concentrated liquid or
aerosol.
The aerosols are packaged in 0.5 to 1 l spray cans for treating
domestic boilers. Refer to the instructions supplied with the product.
The liquid products are available in 1 to 50 l containers. These
concentrated liquids are diluted before application with a spray.
Sprays exist in various forms suitable for their intended use:
- Low capacity (2 or 3 l) spray with built-in reservoir for small boilers
and moderate frequency. Manual pressurisation of the reservoir.
- 5 l spray with separate reservoir, nozzle and connecting tube. The
nozzles enable easy application at the back of the combustion
chamber. Manual pressurisation of the reservoir.
- Motor-assisted pressurisation spray with reservoir, nozzle and
connecting tube. These sprays are intended for intensive use.
28/08/2012 - 300029292-001-02
- Remove the left and right cleaning hatches from the flue gas box
(2 butterfly screws) and use a vacuum cleaner to remove any soot
which has accumulated.
- Replace the cleaning hatches.
8800N063
NXR3i
8800N065
23