Baseboard problem

Alan_6

I have a job where the fintube baseboard is lacking radiation. I cleaned all the fins with a compressor, when I purge the loop, it does not seam to be restricted. Boiler is cycling between 190 and 205. The temperature drop is 12 degrees across the baseboard. When you hold your hand over the fins, it does not feel very hot. The customer says that it use to heat fine. Is it possible, that there is a build up on the inside? Is the a way to clean it, it is 1 " fintube? The baseboard is 20 plus years old.

Weezbo

hmmmm... What size base board/ convector?1 1/4\" ?

1/2 "?

Alan_6

It is 1" convector, and is piped with 3/4", all copper.

Sweet_2

190-205

are you sure the gauge is accurate? Have you taken a return temp reading. Is the boiler short cycling? Whats the amp draw on the pump, sure the pump is moving water?

Alan_6

The pump is oversized, I have pulled the bearing assembly, checked the coupler and impeller. It runs at 3.1 amps, when the zone is open, and at 2.8 amps, when I stop the flow through the pump. It defys all logic!! I even trid restricting the flow to the pump, and forcing a 20 degree split. The aquastat is in-accurate, it is set for 220 degrees. I did replace the temp-pressure guage. I used strap on thermometers, wrapped insulation around them. Took my differential when the boiler burner was off, and both thermometers where on the down swing.

Sweet_2

Alan

What were your temp readings @ supply/returnn???

Wethead7

Baseboard

Does the place have new carpet?? Is the vent on the top open fully?? If none of the above What has changed??

Mike

Darin Cook_3

As wethead said

If it used to work fine, then what has changed? How did you get involved in this? Boiler changeout? It is obvious the BTU's are available. The limited delta T indicates a lack of air flow across the heat emitter. There is a reason why it won't heat properly , you just have to keep playing heat detective. Not to sound cynical, but sometimes it never did work right and since you changed the boiler or whatever now it becomes YOUR problem. I hope that is not the case for you.








Darin

Alan_6

Supply at 195, return is at 183. Same old boiler, the only thing that has been changed is the bearing assembly. The same impellar was used, and appears it was done correct. There is 1.5" clearance from the bottom of radiants, and the louvers are fully open. I am starting to beleive that it has never worked, the owner swears it did. 26 feet of radiant, 768 square feet, high trim style base board. Would like to see at least 40 feet of baseboard in here. It takes 3 hours to raise room 1 degree. And overnight the temperature falls on those 0 to 10 degree nights. What is so odd, when baseboard is new you cant leave you hand on the top of the radiator. Here it dont feel to hot.

Sweet_2

26 FT

of baseboard is around 14ft shy for 768 sq/ft @30 btu a ft. What was outdoor temp. when BB was new? THis may be the difference between then and now. Sounds like this problem was preexisting