Monoflow Hot water system question

Balazs

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Balazs

Monoflow Hot water system question

Hello all you Pros out there,

We recently moved into our home. Right after we got some flood so the boiler had to be replaced. We did some update on the house and decided to put back a cast iron radiator that was installed before (we found it in the basement) and to add two baseboard radiators. All the existing radiators are cast iron (various sizes) and all of them is teed off with a monoflo tee on the return side. There is only one heating zone, where the main is split into two loops in the basement. The circulator is on the return side.

We only added one monoflo and a regular tee to the main as we found existing tees for the other tow radiators.

The two new baseboard radiators (A and have some horizontal piping even with some sections that go up and down again before reaching the radiator. Possible air trap?

After firing up the system the old-new (C) cast iron was working, none of the new baseboard radiators got heat and also an old cast iron remained cold (D).
We bled all radiators to the point where only water was coming from them.

After reading through the hot water help on this site (extremely good!!!) I figured maybe there is too much resistance in my baseboard radiator (A and and added a monoflo to the supply side of radiator (A) too. Didn't help. Strangely (D) the one that didn't warm up originally warmed up, but other two radiators (E+F) were not getting too hot.

My suspicion is on the circulator now. Is it possible it's not working well? The electric motor is too hot to touch.

any suggestions are welcome.

Balazs

Unknown

why was?

Few things here, yes you are correct regarding not getting the flow thru the problem radiators. Can't really help unless I see the job or perhaps some pictures. Anotherthing, why was the boiler replaced with pump on the return ? A real boiler pro know its always better on the supply side of boiler, pumping away from tank..

bruce_21

You have an air trap on the lines to the new baseboard rads if the piping goes down then up, even slightly, then down again before going back up to the main. Correct the piping so there are no traps or install automatic air vents or bleeders at the high points. Also check that the monoflo tees are installed in the right direction. Is the circulator new or old? Small cartridge type which is water lubricated or with a motor and shaft/coupling you can see spinning? Water lubricated will be same temp as pipe next to it.

Balazs

I already thought about the pump being on the return... Is that a big problem? Could I be missing the flow because of that?
The only reason it's there that we put it at the same place where the old system had it. We just copied it. Must say that the old circulator looked much stronger than this one.
What would be the solution?
Here are the pictures...

Balazs

thanks for the answer. I have posted the critical areas of the radiator (A and . It seems that (A) goes up that slightly down before turning up to the radiator again.

(B) goes up from the main but than it goes around a stud and than goes up to the radiator. Do I have an airtrap than?

I think the monoflo tees are in the right direction.

The circulator is new, see the pics in the previous post. It was definetly hotter than the water in the return pipe.

thanks for your answer.

Balazs

z

Balazs

Still looking for help

Check out the pictures I posted maybe it makes more sense than. thanks...

Balazs

The solution

It turned out that the circulator was broken and two monoflow tees (not the ones I installed) were facing the wrong way. Fixing these eliminated the problems.
thanks for the help.
Balazs