Not getting heat from Central Boiler Classic 5648 model

[Bart]

 Not getting much heat from heat exchanger in the basement. Don't know if it is somewhat plugged or what. If so what can I do to clean without removing it out of the plenum. The water line is hot going to it but not getting hot air in the house.

[beenthere]

Welcome to the Forestry Forum.

You say the water is hot going, now how does it compare to the temp leaving (returning) ??

[doctorb]

More likely a pump is not running.   Agree with beenthere.  Check water temp at inflow and outflow of the heat exchanger. 

[xalexjx]

is it a new installation?

[coxy]

could have a air pocket in the line take the line off the other side of the heat exchanger and let it run a little while I have to do it on mine some times

[r.man]

Hot in cold out at the coil while the fan is running generally denotes low flow or no flow. Typically with mine it meant low water and the pump was airlocked. I would add water and also flood the incoming line and pump by closing the valve in the outgoing pipe while forcing water into the outgoing side of the pump. The way mine is piped I can force house water through the whole system, one half at a time.

[Engineer]

Not getting much heat from heat exchanger in the basement. Don't know if it is somewhat plugged or what. If so what can I do to clean without removing it out of the plenum. The water line is hot going to it but not getting hot air in the house.

Check that you have enough water in the water jacket in the boiler.  I had a similar problem as you and adding water to the boiler solved it.

[albirk]

Check the pump the impeller might be gone. If that checks out to be good then check for a air lock. If it is a new install air locked.

[r.man]

I have always wanted a flow sensor in my line, not an electronic one, a mechanical. Saw a couple a few years ago on a ground source heat pump. Those ones were for cold water in a clear vertical tube with a visible weight inside and graduations etched on the side. With more flow the weight was pushed higher.

[beenthere]

How many gpm are you wanting to measure? See there are some that go down to .25 -2.0 gpm and there are others (Surplus Center ) in the higher end.. i.e. 25 gpm. 

Google "visual flow meter with gauge" for a variety.