Froling pump short cycling

[Newfiestang]

I saw that earlier...but with the buffer tank system, I do not see how anything other than #4 is an option.

My system is set to hydraulic system 2 and working fine with buffer tanks.

 

[Smoothride]

Well, I guess then, that is something to try. Thanks.

 

[Newfiestang]

Well, I guess then, that is something to try. Thanks.

Im not so sure thats a good idea unless you know every setting of your system and what its set to. I think when you switch the type of hydraulic system when switched changes a bunch of other settings in the software.

 

[Caiden]

A quick question on storage tank sensor location. Is the top buffer tank sensor located a little way inside of the tank? I'm thinking between the top 5 - 10% of the tank. That's where mine is located and I have no issue. I'm thinking if it's located on the inlet pipe you may have greater heat loss and the temperature in the pipe is dropping a little lower than the buffer tank if there is no flow. Triggering the pump to come on.

I don't have a manual in front of me but if you wanted to increase the differential between turning on and turning off it would probably be referred to as a "hysteresis" value.

chew72, My tanks are about 72" tall and the top tank sensor is at about 58". All my sensors are in 1\2" wells. I purchased the tanks recommended by the supplier. Thanks for the "hysteresis" term. I will look around in the settings to see if I can find that. That is a big problem of mine is understanding what some of the terminology refers to. Thank you for your input.

 

[Caiden]

Caiden, we're looking at installing a Froeling S3 Turbo with two 300 gallon tanks, but we're having some trouble figuring out how much it would cost us installed. Would you, by any chance, be willing to share a breakdown of your costs for the various components and materials, as well as the installation costs billed by your installer? I know that every system is different, but I think I'll be able to extrapolate since I have some sense (a list) of the various controls, valves, fittings, etc. planned. I'm just having a really hard time getting a straight answer, and the current estimate for the fully installed boiler and storage tanks and DHW with pump sensors, controls, fittings, valves, and piping is substantially higher than any estimates I've found online for a P4 installation with two 300 or even larger tanks and DHW and close to double what I've found for comparable systems with an S3 Turbo. I can't quite figure out why the numbers are so much higher except that the labor is a lump sum, and I have no sense of how much actual installation should cost. I would be incredibly grateful for any information!

Mila70, I had a very hard time finding someone to even give me estimates. Heating companies in my area are busy and were not really looking to take on a job of this size. I did finally get 2 estimates. I had the S3 Turbo 50 installed with two 300 gallon tanks (used an existing Boiler mate) and all the recommended controls. I didn't want to cut any corners (which is why I am a little frustrated with my situation now). Both quotes were comparable for equipment. The installer that I chose came highly recommended and is a expert with solid fuels. The cost of just the equipment was about 23K. Piping and fittings and all other necessary equipment with the labor was about another 12K. If I could get to the bottom of the short cycling I would be very happy with the system also. I would say that the 600 gallons of storage would be minimum. I almost went with the 440 gallons and it would have been a stretch to make that work for me. I am heating about 3700 sq. ft. with a fairly tight construction. I hope this helps.

 

[Caiden]

All my sensors are in thermowells in the the tank....or tanks in my case as i have two.

And i have 4 sensors, 2 in each tank. These are located apprx 12" from top and 12" from bottom in each tank.

Yes if the sensors are just strapped on to an uninsulated pipe they will definitely see lower temperatures and not accurately measure the internal tank temperature. The sensors will also see a delay in this configuration.

That is interesting. I have 4 sensors as well and my installer put the all in the same tank. The tanks have 4 ports on the side and they are installed top, mid top, mid bottom and bottom. I wonder what the best is?

 

[Caiden]

Im not so sure thats a good idea unless you know every setting of your system and what its set to. I think when you switch the type of hydraulic system when switched changes a bunch of other settings in the software.

I was able to catch the cycling. I have the pump to 25% minimum. When it is in "off" the pump comes on at 100%. If the temperature in the boiler or the top tank sensor stays the pump will run for 12 seconds then go to 25%. If either of the temps move to turn the pump off it will restart at 100% again.

 

[chew72]

Similar self install, Froling 30kw FHG, Two 500 gallon tanks, Heat exchanger for DHW and 50' of insulated line between buildings plus all the the fittings etc $20-22K

 

[djbutt]

I had the same short cycle time on my Froling. As the boiler cools after a burn the pump would kick on and off every few seconds for a long time. I could hear some water hammer in the pipes when it was happening.

I solved it by installing a time delay relay in the wiring for the pump. The relay will not turn off the power to the pump until it sees a prolonged off signal from the boiler. Every time the boiler tries to cycle the pump off then on again it resets the timer in the relay. The timer is adjustable. I think mine is set to wait 2 minutes. Its been 10 years this way with no issues.