Slowing down flow

Ill be happy to shoulder the blame for some of this topic - as I spew a lot of drivel about flow.

Sending and returning similar temperatures is simply circulating energy to no result. If you sent out 160 degree water and it came back at 160

daaaa -- The Water, didn't give up any of its energy to the load!

Slowing the flow allows the water time to release the energy is carry's - to the radiation - and into the dwelling = comfort

Releasing too much energy to the loop or/and returning water that is too cold is not right either and that is the most common bug I see in retrofitted systems.

Recently we have had a long thread that appears to be the opposite - a loop that will not flow enough and will not heat a space -- -- but thats another thread

Kind Regards
Sting

Yes...that IS a long thread!..soon to come to a conclusion with results to follow

I can hear the flow through the system now, which I do not like

Might be air in the system...
The coal boiler is bigger so...
Something happened during the install...

I assure you there is no air in the system. I have bled it all out and the air scoop got the rest.

Coal boiler aquastat - 160/180 diff of 10
Oil boiler aquastat - Back then I didn't mess with it, but when we installed the coal boiler, we did, and I have no clue what it was at before. I turn this down to 140/160 in the summer for hot water.
Pump - B&G NRF-22

I have the oil boiler valved off from the system when using the K6.

This morning the outside temp was 22*.
Thermostat setting - 68*
Inside temp - 67* (with the thermo calling for heat)
Boiler was at 175.
Supply temp reading on pipe mounted thermometer - 155
Return temp reading on pipe mounted thermomter - 152

Last night I opened up the return valve and the loft loop 100%. I valved off the shorter loop to about 1/2.

Before anyone suggests installing wells for more accurate readings, please understand that I am only looking at the differences between the temps. I can (and have) brought home a laser thermometer and FLIR Camera and measured the supply/return temps more accurately with the same differences.

Thanks to all and I hope we can figure this out.

Ok, boiler at 175, supply water at 155.

Water going to finned radiation is too cold. But why is it too cold?

Check possibilities- Bad gauge on boiler? Water being blended some where via cross connection? Flow issue?

Pictures or schematic of piping might help.

steamup wrote:Ok, boiler at 175, supply water at 155.

Water going to finned radiation is too cold. But why is it too cold?

Check possibilities- Bad gauge on boiler? Water being blended some where via cross connection? Flow issue?

Pictures or schematic of piping might help.

The supply temp is reading 155 because of a surface mounted pipe thermometer. These are known for not taking accurate readings of the water inside the pipe. The water leaving the boiler is at 175*

Wrap the pipe with some insulation to help the strap on read more accurately.

Confucius say " man with one watch knows what time it is, Man with two watches is never really sure". Better verify which watch is correct.

Hollyfeld wrote:Oil boiler aquastat - Back then I didn't mess with it, but when we installed the coal boiler, we did, and I have no clue what it was at before.

It could have been higher than you realize...maybe 200 to make up for the lack of radiation.

Hollyfeld wrote:Supply temp reading on pipe mounted thermometer - 155
Return temp reading on pipe mounted thermomter - 152

That seems really odd if the boiler's temperature gauge reads 175.

Question - Is the Keystoker aquastat wired so that it gets a signal when there is a heat call? I'm wondering if the stoker is just operating off the low limit and your gauge is messed up as well.

Rob R. wrote:

Hollyfeld wrote:Oil boiler aquastat - Back then I didn't mess with it, but when we installed the coal boiler, we did, and I have no clue what it was at before.

It could have been higher than you realize...maybe 200 to make up for the lack of radiation.

Hollyfeld wrote:Supply temp reading on pipe mounted thermometer - 155
Return temp reading on pipe mounted thermomter - 152

That seems really odd if the boiler's temperature gauge reads 175.

Question - Is the Keystoker aquastat wired so that it gets a signal when there is a heat call? I'm wondering if the stoker is just operating off the low limit and your gauge is messed up as well.

I thought it slightly odd that the pipe mounted thermometers read such a lower number, but researching them online I found that they arent that accurate.

I have considered replacing the gauge that came with the keystoker with a newer one - perhaps it is time!

The aquastat is wiring into a Taco Zone Panel. When the thermostat calls for heat, the stoker starts up.

@ Steam - are you suggesting wrapping the pipe with fiberglass insulation where the thermometer contacts the pipe, or just around the back of the thermometer and pipe, leaving the metal to metal contact? I like this idea!

Yep verify the boiler thermo...

@ Steam - are you suggesting wrapping the pipe with fiberglass insulation where the thermometer contacts the pipe, or just around the back of the thermometer and pipe, leaving the metal to metal contact? I like this idea!

Leave the metal to metal contact and wrap the pipe and thermometer in a little blanket of insulation with just the face poking out, like a little baby.

This helps elminate convection heat losses to the air that causes some of the errors of surface mounted temperature readings. Keep in mind surface mounted sensors have a time lag waiting for the pipe to heat up, so even with the insulation, it will respond as fast as a well mounted thermometer.

I have ramped up the temps to 170/190 (this morning) in preperation for the cold weather tonight, the balancing valve on the short loop closed 50% and everything else is open. I also turned in the feed nut one turn.

If I happen to find some loose insulation somewhere I will wrap the gauges up and see what they read.

I havent had time to find and buy a new gauge, but that is my next on my list of things to do with the boiler. I hope old man winter comes along and allows me some time for testing.

Think its possible to valve off the boiler, relieve the pressure, drain it down a tad and then safely remove/replace pressure & temp gauge without having to shut it down 100%?

Hollyfeld wrote:Think its possible to valve off the boiler, relieve the pressure, drain it down a tad and then safely remove/replace pressure & temp gauge without having to shut it down 100%?

Yes, be sure to prepare so to minimize the time that will be involved, and leave the PRV *cracked* until you're done. Thoughtful planning will help minimize amount of air that goes through system on completion.

Was this system working well when fired on oil? It is baffling that a simple boiler addition causes this kind of a problem. That K6 will blow you out of the house with capacity, so something is just plain NOT RIGHT! Can you scratch a flow diagram for us, please. Also is this a primary, secondary setup? Somehow something simple is being overlooked. I didn't read all the early posts, but if we go back to the KISS principal, we WILL find the answer, quickly. I assume this must be a 007 or similar circ, so why is there any consideration of flow being reduced? Are you sure something stupid, like a washer, piece of solder, a piece that plugs up something did not get inside the piping? I HAVE seem this, and no amount of formula crunching will resolve that one!!!! Understand that Einstein probably did not do the sweating, fitting or checking before this was installed. We ALWAYS check pipe just in case some idiot stuffed a piece of stryfoam in the end of the pipe at the warehouse....candy wrappers, ciggy packs......it happens every day....and these idiots reproduce...and vote. Ever stuff a potato into an exhaust pipe of 'a friend' back in the day? You get the idea. Those problems are much harder to resolve.

Hollyfeld wrote:Think its possible to valve off the boiler, relieve the pressure, drain it down a tad and then safely remove/replace pressure & temp gauge without having to shut it down 100%?

Dangerous put possible.

Let the boiler idle down to 140 deg. or below to be a little safer.

I took a face full of 140 deg. water once, hurt like hell and left me with a "sunburn". I was lucky, could have been much worse.