On a routine basis I get quite an obnoxius odor coming from the furnance for the boiler of my steam heating system. I thought it might have been a gas leak, so I called the gas company. The gas repairman thought the odor might be coming from ashes in my furnance. He said he though each time the furnnce kicked in it heated up the ash, whichwas full of mercaptans which was giving off the obnoxous odor. If this is true, how do I clean the system and is this odor toxic? Lately all the plants near my steam radiator have died. They have been there for many years and within days they died.

My suggestion is to call a professional to look over your system. I am sure it needs to be cleaned and checked for proper combustion. These items are best left to a professional who has the proper tools and the knowledge to use them.