And because of a fly ash blockage, he may want to install a "T" with cap for easy cleaning. I have a "T" with cap on my boiler. Every now & then, I pull the cap and vaccume when tending the boiler. Oliverfranco b wrote:The small round Godin was usually piped to the bottom. If you pipe yours at the bottom the heat exchange will probably be more effective. Be aware however that piping it at the bottom will create a trap for fly ash that could restrict the opening and that it why it is piped to the top for safety reasons.