KA-4 New house, poor design, requires over 200F baseboard!

Hi guys,

When I moved into our new house this summer the oil boiler high limit was set at something like 240F. I turned it down as far as it would go(off the top of my head that was 210F). That's as low as this cold start controller would go. Now I know why they use a higher pressure in my system ~22psi. Must be to raise the boiling point so they can run the hotter water.

What I've found is that on cold days, in the single digits, my upstairs doesn't get past low 60s, maybe 65F. Downstairs does a bit better.

I'm in the process of installing the KA-4(hopefully next week since I'm using a full tank of oil per month) . Does anyone see any issues with running the high limit of the KA-4 in the 200s?

Thanks,
beatle78

What is the output of the oil boiler? Does the oil boiler actually reach the high limit during a heat call?

The high limit being set that high is a dead giveaway that something isn't right. As I recall the house is about 2800 sq. ft?

How much radiation is installed?
Have you pulled the covers from the baseboards to see if the fins are clogged with dust?
How is it setup?
How about some pictures of the existing boiler and piping?

I don't see any problem running the K4 at 200 degrees (no pex right?) if that is what it takes to stay warm, but you have some work to do before next winter.

FIRST

do a heat loss calculation

THEN plan the system and its operation temperature

Too late now, the house is built, and the baseboards installed. I think the high temperature was a bandaid to poor design, too few feet of baseboard, and maybe poor insulaton.
In my experience, which is about .0001% of Sting's, hot water baseboard systems are designed to run with 180* water.

Maybe this is some new 'economic' measure to use less copper and baseboard length, thereby saving the builder money building the house, at the expense of the homeowner's heat bills.

I see no reason that the KA-4 can't run at 200" but you may have more issues than normal with temperture spikes past the intended high limit.

After a call for heat, after the stoker has filled the bed with burning coal, the water reaches 200*, then the thermostat is satisfied, the circulator stops and the big bed of hot coal has to slowly burn down to an idle fire,, all that extra heat is going to push the boiler temp up. If the running temperature was at 160=180, then there is more room to heat before hitting either a dump zone temp or the PRV's trigger.

Just how big is the oil tank that is being used each month, in this mild weather??

Greg L.

LsFarm wrote:Maybe this is some new 'economic' measure to use less copper and baseboard length, thereby saving the builder money building the house, at the expense of the homeowner's heat bills.

That trick was popular in post WWII housing developments.

He needs to make sure the installed radiation is working properly, i.e. proper flow through the pipe and airflow through CLEAN fins.

LsFarm wrote:After a call for heat, after the stoker has filled the bed with burning coal, the water reaches 200*, then the thermostat is satisfied, the circulator stops and the big bed of hot coal has to slowly burn down to an idle fire,, all that extra heat is going to push the boiler temp up.

Better upgrade the expansion tank.

Keystoker's recommended high limit setting is 220*. So yes, no problem. The Ka-4 is capable of heating your house with no problem. As others say, somethings not right. Lack of radiation, poor design, lack of insulation, etc.. We have some good "Hydronics" men on this site. Sting is one of them. Oliver

beatle78 wrote:boiler high limit was set at something like 240F.....
my upstairs doesn't get past low 60s, m

Just because it's set at 240, or 210.... does it actually reach that temperature? As mentioned, check for dirty fins in the baseboard. Then watch the boiler temp while it's in the middle of a call for heat. Perhaps the wrong nozzle is in the burner? And, as mentioned, perhaps the pumps are not doing their job.

If all is OK and it actually does not have enough baseboard, I'd look into adding more, or replacing what's there with high output.

beatle78 wrote:I'm in the process of installing the KA-4(hopefully next week since I'm using a full tank of oil per month) . Does anyone see any issues with running the high limit of the KA-4 in the 200s?

No problem.

ok, first, here's pics of current setup & KA-4 in place.

I'll try to answer all the questions here.(thanks for the responses)

-I'm not sure what the BTU of the oil boiler is. I'll have to crawl behind it and check. The nozzle listed on the service tag did seem to be a bit small.
-I believe the boiler gets up to temp on the cold days. The baseboard does get hot. I will double check on the next cold snap.
-The oil tank is a 275 gal tank.
-This has been a VERY mild winter
-House is around 2800 sq ft. BUT I gutted the 3rd floor & removed that zone, and I gutted another room that I need to remove the baseboard from b/c it shares a loop with some other bedrooms(I know I lose btu's here b/c it's like heating an attic. Some of this is my doing, but they must have had issues before I moved in b/c the boiler was turned WAY up. Like 240F or higher.
-We are doing some remodelling this summer, I plan on redoing a lot of this system as well as run NG to the house. The house has 3 zones, the way I want to do it, I need at least 6(not including the indirect tank, but we'll save that for another exciting thread when the time comes.)
-I've installed a 1980's Federal Airtight cast iron catalytic wood stove & taught my wife how to use it. That's starting to help with the oil consumption.
-Good point about the temp overshoots with the high limit set at 200F. I think I'll be OK as long as my expansion tank is big enough b/c the boiler was set to 240F or higher when I moved in. What I don't think will work is my current high temp Aquastat. I think it maxes out at 220F.

How many feet of baseboard is on each loop? Is the piping feeding it 3/4" or 1/2"?

You didn't say if you checked the baseboards for cleanliness...that is important. Also make sure there is clearance for air to enter the baseboard...it isn't uncommon for carpet to be installed tight to the element and block airflow.

All good information

note - everyone is asking you questions that should be addressed in a proper heat loss calculation of the load

note 2 -- it makes no difference if the boiler is set to run at 140 or 240 or infinity -- what makes a difference is the loop(s0 are not carrying the loads -- so the correct question is ====

wait for it

what are your supply and return temperatures per loop of zone?

Kind regards
Sting

1. Yes, I did a quick scan and all fins seemed to be clean. There is rugs installed. I will double check the clearance I have between the rugs & the bottom of the baseboard
2. 3/4 copper to each zone. I couldn't tell you how much fin tube is on each zone. I'll have to go measure when I get back next week.
3. Good question. I don't have an infared thermometer & there is no probe on each loop. I can tell you this, I can burn my hand on the return temps, lol

I'm betting there is carpet and padding combining to close off air flow into the bottom of the baseboard enclosures. They will not put out much heat but will be hot. They work on convection and must have air flow to give off heat.

coalkirk wrote:I'm betting there is carpet and padding combining to close off air flow into the bottom of the baseboard enclosures. They will not put out much heat but will be hot. They work on convection and must have air flow to give off heat.

I too am guessing carpet/padding.