Basement Rads Cold...

KGK

I have had a new 3 zone hot water rad system installed recently. The orginal system consisted of a gravity fed system (from the late 40's) which was converted to a circulator system at some point after that. The circulator system worked fine and all rads were hot. We have recently renovated (added about 1400 sq ft) and at the same time upgraded the heating system. We kept the original piping and rads and then added new boiler, primary / secondary piping, Taco 3 zone controller and Stelrad steel rads for the second and third zones. The original piping is zone 1 and included a bypass and temp mixing valve to keep the water from getting too hot for the old cast iron rads.

Here is the issue - everything in the new zone 2 and 3 seems to work fine. Most of the original circulation system also seems to work EXCEPT that two of the rads in the basement no longer get hot.
The original heating contractor said this was an air trap problem. I don't think so since I have bled about 30 litres of water from each of the cold rads. The water ends up coming out warm by the end of the massive bleeding, but the rads then rapidly cool again, even though the other rads get quite hot. During the bleeding the TOPS of the rads get warm, but the bottoms stay quite cold. Is this weird?

Can't really provide a piping diagram, since most of the pipes are enclosed in ceilings and walls - I could guess I suppose, but would not be sure.

The original installation company seems to have abandoned us. They are "too busy" to get back to us, have missed several promised dates and are no longer returning calls. After six weeks and 8 phone calls we have given up on them.

At this point we are at a loss and looking for ideas. Ready to call in another heating contractor, but would like to have some ideas for them before we bring in someone else. We are a little gun shy right now.

Any help appreciated.

Uni R

Drop the temps...

Drop the temps until that water isn't significantly warmer than the system water and it may start flowing through that branch.

Mike Reavis_2

you have a path of least resistance problem.

Here is what you can try: assuming that they work, shut off all the valves at the radiators on the system where you have heat. Turn on the heat. If you have an air problem in the basement radiator, it might clear (Let the system come fully up to temperature). If it does not, and if your radiators in the basement are below the level of the supply pipe, then you probably need to have two shut off valves installed on the line leading down to the radiators. In between these two valves you need a tee, with a drain fitting. This will allow you to "power flush/purge" from either side of the piping to remove the air. After the air is gone, you will still need to have the radiators shut down to see if the basement radiator heats correctly. Then you can begin to open the valves to the other radiators by degrees to establish flow in each radiator. A heating pro can do this for you if you have doudts, and concerns. They can also recommend correct repairs.
Mike

Dale

Monoflo

You may want to look to the left, go to questions and answsers and look at "diverter tee systems". You definately have a flow issue where the basement rads are more resistance than the other path the water could take. You could have an old monoflow system where one or both of the diverter tees was moved or removed or something else was done to give the water an easier route. As to the fix, well it depends on how much demo you want to do. I would certainly prove to myself that there's no restriction in the rads and that the piping to them is connected to the system at both ends. Your easiest and most simple solution may be some pex to where you can most easily get to a hot pipe and then a tiny pump so the offending rads are there own little zone. Let us know what you find.

r.mhrin

steam heat

Lots of bnging & no heat ..suspect traps or cages in two pipe system.Large trap that is diff. to understand its function.Suspect it is a return water problem .At times furnace kicks on & off every two minutes. Was drained but system loads up again.

KGK

No Heat in BSMT - solved

It took me a while of experimenting with the different solutions that people posted (BTW thank you everyone), but the problem has been solved.

It actaully turned out to be TWO problems that had to be addressed individually. The first rad had gotten cold and the water was no longer circulating to it because, I suspect, one of the pipes going to it was under the floor. For that one lowering the temp in the rest of the system until it was not very warm at all seemed to work, the rad started getting warm as the system warmed up. We gradually raised the system temp and that rad was working fine since then.

The other rad was more of a challenge. It seems that when the systme was drained for some reason the contrator decided to adjust the controls on two rads on the first floor that sit on either side of the pipe feeding the basement rad. Since we were not sure about the pipe connections this threw us off. What we everntually did is completely shut off the other two rads and force all the water flow through only the basement rad. this got things going down there again. After that we turned on the two rads on the main floor, but not completely because if the valves are completely open there is an easier water flow route through those rads rather than the basement rad. Eventually we found a nice balance between the three rads and everything works fine.

Thanks again for everyones help.

BTW The heating contractor still has not called me back . . .