Termovar Loading Unit on Tarm Solo Innova causing thumping

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K

kopeck

Minister of Fire
Mar 24, 2011
536
Maine
Two times in the last two days when I fire up my Tarm I've got some decent thumping and I traced it back to the loading unit. I've always run the pump on 3, that's the way it came to me, by slowing it down to 2 or 1 the thumping goes away.

I'm not sure if the valve is getting stuck and causing this problem or something else.

The first time is happened a zone opened up and that stopped the thumping. Typically when I start the Tarm I have a few zones calling for heat but it's getting warmer, so I guess that's something to factor in as well.

Anyone else every experience this? I've been meaning to try the pump on 2 anyway, I've been wondering if I was moving water a bit to quickly and not getting as much heat transfer.

K
 
my loading unit came set at 2. left it .worked fine . great unit!! i think the thumping is pressure and temp related. this is the place to ask. Could be pump speed to . some one
here will definately help you out.
 
Here is how the Caleffi MonoBlock is built, I suspect the Termovar is similar. The return fluid flows up through the thermostatic valve and into the eye of the impeller.

In the event of a power outage there is a "gravity gate" check valve #3, that allows gravity flow to prevent over-heating. It could be on high speed with hot, buoyant fluid that check flapper is opening and closing?

hr
 

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The Caleffi looks just like the Termovar to my untrained eye. You can look at the layout here:

http://www.lkacaso.se/Documents/LK Acaso/LK eng/Termovar_Laddpaket_ENG.pdf

What you say seems to make sense, it sounds just like when you quickly close a ball valve while a circulator is running. You can feel the thump in the pipes.

The way I found the problem was I simply turned off the circulator (well, in this case the whole boiler) and it stopped immediately. After that I played with pump speeds and got the same results.

So do you think that in the past just having some zones open was enough to keep the Teromvar happy during the heat up stage? Once it's fully opened I've never heard it make noise.

K
 
What is the boiler pressure when no pumps are on ? It is an over pressure differential that causes this. If you have zone valves they make pressure bypass relief valves to cure this. Meaning your pump is sized too big, especially so when only 1 zone is calling, or boiler pressure is too low. What pump do you have? It won't hurt anything by setting it on a lower speed unless your not maintaining a Delta T of 20 degrees.
 
ALASKAPF185 said:
What is the boiler pressure when no pumps are on ? It is an over pressure differential that causes this. If you have zone valves they make pressure bypass relief valves to cure this. Meaning your pump is sized too big, especially so when only 1 zone is calling, or boiler pressure is too low. What pump do you have? It won't hurt anything by setting it on a lower speed unless your not maintaining a Delta T of 20 degrees.
Click to expand...

I guess I don't know with all the circulators off, I've never paid attention. I do know when everything is cooled down, like when I'm ready to start a fire it's about 15 psi, but usually at least one ZV open and my system circulator is running (that wasn't the case last night, all the zones closed but I didn't note the pressure). When everything is hot, like at the end of a burn it's at 19/20 psi. The circulator on the Termovar runs for the duration of the burn.

I was kind of under the impression, like hr, that the circulator speed on the Termovar wouldn't really matter but right now it does.

This morning there was no thumping, one zone was open when I started the Tarm but I left the speed control set on 2 from last night.

K
 
Oh and the Temovar has a Grundfos UPS 15-60 CIL on it. That's just what they come with, I didn't get to choose.

Or at least that's what I think I have. So on 3, if I'm doing the math correctly that's 12 GPM, the main circulator is a Taco 007-f5 with they list as 0-20 GPM.

K
 
kopeck said:
Oh and the Temovar has a Grundfos UPS 15-60 CIL on it. That's just what they come with, I didn't get to choose.

Or at least that's what I think I have. So on 3, if I'm doing the math correctly that's 12 GPM, the main circulator is a Taco 007-f5 with they list as 0-20 GPM.

K
Click to expand...
My Laddomat is noise free, it has a different style of check valve though. It may be as IHW said, that its the check valve. Try pulling it out once & run without, Randy
 
Singed Eyebrows said:
My Laddomat is noise free, it has a different style of check valve though. It may be as IHW said, that its the check valve. Try pulling it out once & run without, Randy
Click to expand...

I'm not sure I can remove it.

Not sure how this factors in but I'm pretty sure I can hear that check valve (or something in the loading valve) making a little jingling noise when the loading unit pump isn't running but the system circulator is,. Obviously nothing like the thumping that I get when it's running, that you could hear up stairs and feel in the pipes. The jingle is very faint and you have to be right beside the loading unit to hear it.

This is my pipe layout, the only difference being that I use a loading unit and not a separate pump/Temovar valve:

wood-boiler-schematic-w-sto.jpg


K
 
You can't simply remove that "backflow preventer" from a loading unit. Without it the circulator will short circuit and spin its wheels. It can be replaced with a piece of solid brass sheet metal to block it off but you will give up the gravity flow feature of it. Depending on how your system is plumbed this may not be an issue.

If you look in the box the loading unit came in you might find that brass piece in there to give you the option.
 
Just to confuse things more....

I think I was showing you folks the wrong loading unit, I'm 99% sure I have the LK 810 which is a newer version of the unit I linked to above.

What's interesting in the PDF for this unit they have a chart for not only liters/h for each pump setting but also KW/H for each setting. I'm going to have to go home and make sure I have the right model but just ball parking it setting 3 can move way more kw/h then my Innova 30 is putting out. I'll have to convert the l/h to GPM to see how that stacks up as well.

You can remove the check valve and plug it as well but it's an extra part that doesn't come with the unit.

K
 
DaveBP said:
You can't simply remove that "backflow preventer" from a loading unit. Without it the circulator will short circuit and spin its wheels. It can be replaced with a piece of solid brass sheet metal to block it off but you will give up the gravity flow feature of it. Depending on how your system is plumbed this may not be an issue.

If you look in the box the loading unit came in you might find that brass piece in there to give you the option.
Click to expand...
Thats opposite to what Zenon said with the Laddomat. When the capacity wasn't enough with the 40kw boilers he advised to take out the check valve & that solved the problem, Randy
 
Depending on the style of check, many of them reduce flow and add lots of head. I know Taco and Grundfos both have curve charts with and without checks. How much head you have will determine how much flow you have. It would be 12 gpm if the head is 0, but if you have 10' headloss thru the tvalve itself (for instance) it will only pump 1 gpm. Your operating pressure is fine, unless you have a zone that is more than 25' above the boiler. Plus you have 2 or more pumps on in series at any call for heat the way its piped. This plus the mixing valve pump gives you 3 pressure differentials. Any reason its not piped primary secondary ? The only way that works correctly is if all the pumps are pumping the exact same gpm. Not including the mix.
 
kopek, it sounds like you have the LK810 Loading Unit. Before this unit is installed, you need to swap the factory installed swing-check valve for the solid plug that is in the little baggie in the LK810 box. The swing check option is to allow for gravity circulation to thermal storage during a power outage which is much more common in Europe than it is here. The noise you are hearing is this mini flow-check slamming closed when the pump starts.

Not a big deal to swap, just close all the isolation valves, remove the LK810 from the piping and push out the swing check and pop in the plug. Give us a call if you have any questions.

Chris
 
Tarm Sales Guy said:
kopek, it sounds like you have the LK810 Loading Unit. Before this unit is installed, you need to swap the factory installed swing-check valve for the solid plug that is in the little baggie in the LK810 box. The swing check option is to allow for gravity circulation to thermal storage during a power outage which is much more common in Europe than it is here. The noise you are hearing is this mini flow-check slamming closed when the pump starts.

Not a big deal to swap, just close all the isolation valves, remove the LK810 from the piping and push out the swing check and pop in the plug. Give us a call if you have any questions.

Chris
Click to expand...

Thanks Chris,

Just sent you an email.

K
 
Tarm Sales Guy said:
kopek, it sounds like you have the LK810 Loading Unit. Before this unit is installed, you need to swap the factory installed swing-check valve for the solid plug that is in the little baggie in the LK810 box. The swing check option is to allow for gravity circulation to thermal storage during a power outage which is much more common in Europe than it is here. The noise you are hearing is this mini flow-check slamming closed when the pump starts.

Not a big deal to swap, just close all the isolation valves, remove the LK810 from the piping and push out the swing check and pop in the plug. Give us a call if you have any questions.

Chris
Click to expand...

But wouldn't you want that gravity circulation overheat protection?

Or is there a separate redundant loop for that?
 
Like Chris sad I have a separate no-power-overheat loop that completely bypasses the loading unit.

Now I just need to find the plug that goes in the loading unit. It seems like a simple fix...I hope it works out that way.

K
 
Installed the plug and the thumping seems to have gone away.

Thanks guys,

K
 
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