Q how do i know how old my boiler is? Thank you for subscribing to recieve tips & coupons from benjamin franklin plumbing. Good for rv's i have been using this for our rv septic and it seems to be doing the job of getting rid of odors and keeping things flowing i like that it is a natural alternative to the chemical laden types and less expensive too! Your boiler is over years old. Call us on or alternatively use the form below and we will call you back!.