My daughter recently bought an old home that is in excess of 90 years of age. She is presently trying to clean-up the basement, prior to insulating it, and I am assisting her in the removal of all the “old” stuff that is no longer used, or serviceable. Towards this end, in removing old galvanized iron piping and replacing it with copper, we have determined and confirmed that a new hot water system was installed in the house, some time ago, but we don’t know exactly when. The ‘new’ system has a Trade name on the furnace, “Weil- McLain”. This new system was apparently quite expensive, and we have heard that its cost was somewhere in the vicinity of $15,000 dollars. The system appears to have a circulating pump attached to its side.
Also, in between the ceiling joists of the basement, there is a hot water holding tank that appears to not be connected to anything; one end of the tank has a galvanized cap covering either a water inflow, or outflow, I’m not really sure which, and the other end has connections to what seems to be a surplus, and unnecessary, bunch of galvanized piping, and does not seem to be connected to the “new” water system at all. My question is: will it be OK to remove the excess holding tank and all the piping that we think was used originally to service the original heating system? We eagerly await your response, and will send you more information if it is required, and requested.
The hot water heating system described is relatively simple in concept, but has many controls and safety features installed that are complex and whose function may be difficult to understand. This style of heating systems is made up of a series of pipes, filled with hot water that circulates throughout the home and give off heat from large, warm radiators in individual rooms. The “Weil–Mclain” furnace described is actually a natural gas fired boiler that heats the water that travels through the system, aided by the circulation pump mentioned.
The boiler can be simplified by comparing it to a large sealed kettle that is heated by a natural gas flame, which has the excess combustion products vented outside the home. Because the system is mostly sealed, the water will expand as it is heated, and if not controlled, could turn to vapour or steam. If this were to happen in a completely sealed system, the ramifications could be disastrous. We only have to think of a lid blowing off a pot of boiling water to imagine the consequences. For this reason there are several control mechanisms on the hot water piping to allow for expansion of the heated water. Also, there are safety valves installed that will expel some of the hot water if it exceeds a certain temperature or pressure. These controls allow for more even heat throughout the system, and prevent explosions.
The “hot water holding tank” described is actually an expansion tank that allow the system water to expand as it is heated, minimizing sudden changes in pressure when the boiler is fired up. It is an essential part of any system and will cause several problems if removed. The supply and distribution piping attached to this tank may appear to be without purpose, but may have Temperature/Pressure Release (TPR) valves, drains or other critical components attached. The only time this older tank could be removed is if it was replaced with a more modern tank that has a bladder installed, for better performance. The old tank will likely have a drain and valve attached near the bottom for draining out excess water, if the tank becomes water logged. This is a common occurrence and can be remedied during regular servicing.
To answer the last part of the question directly: You absolutely cannot remove the old tank or any of the associated pipes before consultation with a licensed heating contractor familiar with hot water heating systems. Hot water and steam heating systems are not something to be modified or repaired by inexperienced home handymen. Yearly service of the boiler and heating system is critical to proper performance and efficiency. I recommend a complete evaluation to ensure all proper controls and safety devices are installed and in working condition, prior to use. Often, in older hot water heating systems that have been poorly maintained, excess air is present in radiators, expansion tanks are waterlogged, pipe fittings are rusted and leaking, and other deterioration is found. Summer is a good time for evaluation and repairs, as the heat is off and the system can be easily drained and repaired if required.