Boiler Control

Rich_23

> I thought one <BR>
> of the goals for hydronic heat was to keep the <BR>
> flow going

Never heard that one. The goal of any kind of heating is to make the house comfortable, neither too cold nor too hot.

> I have <BR>
> considered thermostatic valves for remaining <BR>
> radiators, but the valves that I can find <BR>
> (Danforth?) are different lengths than the <BR>
> original, making swap out more difficult. The <BR>
> radiators are above and between the monoflow <BR>
> tees.<BR>

Haven't seen your system, so can't say what is needed. Some plumbing could certainly be required. Danfoss valves are very widely used.

> Seemed like running the circulator pump <BR>
> longer after the heat cycle would help balance <BR>
> out the heat.<BR>

If the problem is due to ghost flow when the circs are not running, then running the circs longer could deliver a little more heat to the first floor and thus a little less to the second floor. Modern boilers with internal electronics often have settings to let the circ run for a few minutes after the heat call has ended, but yours may not. There was a time-delay relay device advertised on "Buy, sell, show" on these pages for a while, but not any more. Try hooking up you circulator to run 24 hrs a day and see if that makes a difference. This is a test that doesn't require you to buy anything.

I think it is more likely that this overheating is a result of modern improvements such as attic insulation.

Darin_4

Boiler Controls - 2nd floor too hot.

I have a oil-fired, one-pipe hot water system with a Weil McLain Boiler with a Honeywell Control in a two story house. The second floor stays much hotter (6 to 8 degrees) than the first, particularly on mild (50 degree) days.

When the boiler is not running. I think the remaining heat in the hot water is migrating to the second floor radiators and contining to heat the 2nd floor.

Is there anyway to "smarten-up" the controls? My control looks like it has a single relay controlling both the burner and the pump. Can the pump be made to stay on, say 15 minutes, after each heat call to evenly disapate the remaining heat, similar to hot air systems?

What about adding a setback control to an existing 15 year old boiler?

I am just starting to try closing the upper radiator valves 50%, but it seems a little strange to try and reduce the flow to the upper level.

Any insight is appreciated.

Thanks,

Rich Lowenstein

If you have too much heat in a given location, and you can turn down the radiator valves in that location, what's strange about that? It seems like the first thing one should do! You can also see if there are suitable balancing valves near your boiler, and use those.

In our house, we used to have all the upstairs radiators completely turned off...until we got thermostatic radiator valves, which are smarter.

It's certainly possible that you have convective flow when the circulator is off: this will tend to heat the second floor more than the first floor. Usually forced-circulation systems have check valves to prevent this, but yours could be stuck.

Darin_4

Rich,

Thanks for the message. I thought one of the goals for hydronic heat was to keep the flow going, hence the reluctance to turn down the upstairs valves. I've got the upstairs valves half closed at this point and am trying it out.

I have replaced a couple of raidators removed by previous owners and have installed the thermostatic valveson those. They seem to work well, but are all on the 1st floor.

I have considered thermostatic valves for remaining radiators, but the valves that I can find (Danforth?) are different lengths than the original, making swap out more difficult. The radiators are above and between the monoflow tees.

Seemed like running the circulator pump longer after the heat cycle would help balance out the heat.

What type of thermostatic valves did you use? Do you have a source?

Thanks,

-Darin