Termover valve

[muncybob]

This is something that is mentioned as an accessory on sites carrying Tarm(and elsewhere)...appears to be an all-in-one solution for several seperate pieces. My question is, is this a better way to go rather than seperate components? Seems it may be a bit cheaper(esp. with their "sale" right now) but if one part breaks is the whole unit then rendered useless? Are they repairable?

 

[DaveBP]

If you're thinking of the Termovar "Loading Unit" there are a couple good pdf's here:

http://www.acaso.se/english/index.html

When Bioheat (Tarm USA) imports them they have a Grundfos 15-58 3-speed circulator installed on them to use 120V 60 Hz power. Up to now they don't import (nor up until recently do they expect to import in the future) the model with the "backflow preventer". A pity. I'd buy one in a heartbeat if they did. They are only of benefit to systems with pressurized storage.

Either way, the loading unit is not just a 'regular Termovar' with a lot of stuff added to it. When the return water coming back to the boiler is above the minimum temp the thermostatic unit is designed for, it closes off the bypass completely so that all the water coming out of the boiler is sent directly to system/storage. The regular Termovar always ends up recycling some of the boiler supply water back around to the return for another pass, even when the water is warmer than the desired protection temp. Jim (aka Jebatty) demonstrated this in some tests he did late this winter. How much difference that makes probably depends on your particular systems details. Maybe none at all.

With a good low head install a pressurized storage tank can self circulate through the "backflow preventer" if the power fails. No separate emergency heat dump!The tank has to be installed correctly and I don't blame BioHeat for not wanting to guarantee that it would work where they have no control over those factors. The other thing it can do is extract the last heat in the coals after the circ and fan have shut off, again by self-circulation as long as the boiler water is hotter than the tank temperature. Once the tank is as hot as the water left in the boiler and there is no more thermosiphon it will prevent reverse flow from turning your boiler (hence the name) into a radiator and sucking the heat out of your tank. But the regular Termovar will sort of do this last bit.

The loading unit is ACASO's (Termovar's manufacturer) version of a Laddomat 21, which is used by at least one of our forum members from Sweden and are illustrated on a lot of European websites' system schematics.
Read about them here:

http://www.termoventiler.se/default.asp?webb_ID=110&webbsida_ID=56

But as far as I have been able to find it is only available in 240V. Not an impossible work around but the tranformer and relay add to the cost and is not as elegant as just plugging it into the boiler control and running it.

As you may have gathered by now, I am really interested in these beasts and have until this fall to finish my installation. I'd love it if there were enough people with pressurized storage and interest in the "backflow preventer" model to persuade them to import a batch of them and some of the various temperature thermostatic units to install per request.

Hey Chris! Can you take a 'subtle' hint?

 

[ohbie1]

but if one part breaks is the whole unit then rendered useless? Are they repairable?

I am using the Termovar Loading Valve (since 2/28/09). It seems to be working well. It comes with 3 temp gauges to monitor boiler output, return, and return from heating. It also comes with 3 isolation valves, and the info. says that in case you need to repair it, the system need not be drained, so I assume it can be repaired. It has a 3 speed Grundfos as stated above, so you can experiment for best delta T; mine turned out to be speed 2. Tarm's plumbing diagram did call for a weighted ck. valve on the output, so you will still need that.

 

[flyingcow]

My response is a little simple, as I am a little simple. I have the loading valve on my Innova. I've seen my temps very low from the previous nites firing. Can't remember exactly, but it was cold. Usually when i start a fire, 45 minutes from shutting the boiler door, the system sent 160 water to my house( 195 very close behind it). it works as advertised. Is it worth it? for a simple person as i am, yes very well. I also have the termovar valve in my system down the line. My system is what tarm recommends. It follows their layout. Yes it cost a lot, but?.......................

 

[Chris Hoskin]

Hey DaveBP, thanks for the subtle hint!

EXCELLENT description of the Loading Unit, by the way, thank you very much.

I'll bring up the backflow preventer issue with tech tomorrow and post our (current) thoughts here.

thanks again for the great post,

Chris

 

[Hansson]

Termoventiler the maker of laddomat have some new laddomat models.
http://www.termoventiler.se/upload/bilder_produkter/LM21-60_130x127.jpg
Laddomat 21-60 <60 kW

http://www.termoventiler.se/upload/bilder_produkter/LM21-100_140x130.jpg
Laddomat 21-100 <120 kW

The new laddomats have insulation like the one from Termovar.