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Radiator Issues

I have some questions regarding radiators. We use oil for heating. We have radiators in each room. When we turn on the heat, there is a lot of banging noise through out the house. Also, one of the radiator in one room does not heat up at all. We are trying to figure out how much will it cost to get this fixed.

I called our oil company with whom we have yearly boiler service contract. They charge it by hour($85/hour). When I called, I asked the lady on the phone approximately how many hours it will take to get this kind of problems fixed. She would not tell me which I understand but I need to know how much money are we talking about.

Can anyone tell how many hours of work is it? Again, I understand there are many factors involved but I just would like to know in general how long will it take.

Thanks in advance.

Re: Radiator Issues

It would be hard to set a $$ figure on a repair process that is basically "troubleshooting" and adjustment.

The basic causes of radiator noise can be traced to the fact that radiator pipes, made of metal (copper or sometimes steel) expand when hot water rushes thru them to heat the house; the piping installers have to take this into account when they drill holes in the flooring & install the piping from the boiler & main piping, up into the rooms to connect to the radiators---sometimes they don't make the holes big enough or they don't account for the amount of expansion during the heat cycle for the length of pipe they are installing & there are problems.

Sometimes it's as simple as checking the boiler water temp gauge---if the temp is close to 200 degrees during the heating cycle, that's too high, and lowering the boiler operating temp down to 170 or 180 degrees may be enough to reduce some of the pipe expansion movement, and thus some of the noise.

Another possibility is that there is too much air in the system and the rads & piping are heating up unevenly---removing the air from the system is as easy as bleeding each bleed valve on each rad (starting at the highest point); ; once all the air is out the system often quiets down considerably---the fact that one of the rads doesn't heat at all usually indicates that it is "airbound"---try opening the bleed valve with a screwdriver (usually at the top of the rad)---hold a cup or glass near the valve to catch the water that will eventually come out & close the valve when water appears.

Another possibility is that the pump at the boiler (the pump circulates the hot water thru all the pipes & rads during the heating cycle) is too big for the system; often, a much smaller pump is installed that moves the water more slowly & with less force & this can quiet the system.

Since you said the heating elements are cast iron radiators (rather than copper fin baseboard elements, which also make a lot of noise), the main noise is probably coming from the rubbing noise where the supply & return pipes go thru the holes in the floorboards---as the heated pipes expand, they rub against the floorboards & make a banging noise.

Another possibility is that when the supply piping was installed going to & from the radiators, the installers didn't allow enough slack (especially on a long run of pipe) and the heated, expanded pipe is now groaning against the pipe hangers, as well as the too-small access hole in the floorboards.

Sometimes flexible tubing connectors made of pex, neophrene or other flex material are installed at different points to act as dampers to the noise-causing pipe sections----none of these flexible piping materials were available decades ago when many of these hot water radiator systems were installed, so the flex inserts often work wonders for this application.

Another issue that comes up is whether there is any ACCESS to the piping (so it can be worked on and moved, if necessary), or most or all of the piping is behind closed-in finished walls, some of which may have to be opened to do the job right.

Thus the repair crew may be there for 8 hours before they are able to go thru the techniques listed above before they do an effective job of quieting down the system---the amount of time is anyone's guess

Most service repair techs who work for oil companies have worked on these issues innumerable times and know the repair techniques inside & out---however, if it looks like the ones you hire are not getting the job done in a reasonable amount of time, then by all means get another crew in there.

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