The Need to Bleed?

Nomad

My heat system (Alde) is gurgling. You can hear the fluid circulate. Having lived in a house with radiant heat, that usually means you need to bleed the system as there's some air in there. I notice there is a bleed valve under the back shelf on the left end of the radiator. Anyone experienced this or bled their system?

ChanW

Ours is noisy too, but the gurgling seems to only come from the reservoir tank under the back shelf, so I'm not sure that it's air in the lines. 

Our fluid level's a bit low, so I was going to try topping it off to see if that reduces the noise. Or maybe put something in the tank to reduce the turbulence in there.

Michigan_Mike

This is information from an ALDE manual and there is an ALDE tool that dealers should have to purge air from the system if needed: 

Bleeding the system (manually):

The LPG boiler must be operating and the circulation pump

switched off. Begin by opening the air screws (see the

builders instruction book for their location). Keep them open

until liquid comes out of the spout at the air screw. Start the

circulation pump and let it run for a few moments. Check

whether the pipes and radiators all round the system are

warm.

If the air has not know disappeared, proceed as fol-

lows: The LPG boiler must be operating, and the circula-

tion pump switched off. If in a caravan lower jockey wheel

as far as possible, so that the caravan tilts. Let it remain

like that for several minutes, so that any air rises upwards

in the system. Open the air screw at the highest point, and

keep it open until all the air has escaped. Then wind the

jockey wheel to its maximum position and repeat the pro-

cedure in that position. Then return the caravan to the level

position and start the circulation pump. Check that heat

is present all round the caravan. When bleeding a bogey

wagon or motor caravan, it is easiest to park on a steep

slope or to lift the vehicle up using a jack.

Nomad

Ok, which switch is for the circulation pump? :-)

ChanW

OK, that's as clear as mud...

That probably explains why LG installed the bleeder at the very back of the system, dropping the tongue puts the bleeder at the high point.

When the Alde is in 'hot-water only' mode (on the thermostat, the faucet symbol), the boiler is on without the circulating pump, so maybe that's what they mean here.

Only thing missing then is the bleeder valve for the forward part of the system. Maybe it's such a small system that they figure the rear bleeder is enough?¿?

Actually, the system is simple enough that repeating this a few times should do the job, it seems.

-- 

Chan

2014 'S' Maxx

RTab

I think I've discovered the cure for the gurgling Alde reservoir tank.  I contacted Alde in Vancouver, WA and the tech there suggested I check the pump setting.  Mine had been set too high at "5" and he suggested dialing it back down to about 1.75.  This did the trick!  The pump dial is located on the side of the Alde unit where all the plumbing is.  Look at the very bottom by the floor.  I will post pics of where to find it below.  Note we have a 2015 T@b model S.

ChanW

Thanks RTab. Ours has been too 'gurgley' from the get-go.

Others have talked about it here, too. 

What color is it in your photo? 

I'll have to go dig out the Tab's doorway and figure it out. 

Edit:
I've checked out ours, looked the hoses over thoroughly, found the circulating pump on the lower hose, and can see no adjustment knob anywhere. I was able to pop the cover off the pump easily, and found nothing of consequence inside. A large capacitor, and a small circuit board.

We have the 2014, which was one of the first with an Alde unit, so perhaps they added the variable speed pump on the later installs.

Hmm. I might have to put up with the gurgling noise.

Nomad

The adjustment is the dinky little red knob by my thumb.

ChanW

We'll I've found that there are two pumps available for the Alde (pictures below). I see the 'little red knob' that you guys have, in the upper photo, which I don't have.

It sounds like the one installed in my Tab is designed to have the speed control integrated with the thermostat control. I think the simple thermostat control that's in the Tab isn't capable of controlling the circulating pump speed.

DurangoTaB

Gurgling is not only a nuisance, but greatly decreases the heating efficiency...

Nomad

I had radiant heat in my house for 30 years and a gurgling sound was always bad. Meant you had air in there somewhere. Most water-based radiant systems have an expansion tank that allows the air molecules to escape. Glycol systems don't suffer from escaping air - they're more like sealed systems - so I've heard.

The T@B system has the glycol level tank and the noise seems to come from the glycol sloshing around thru there. I've thought about buying some sound-dampening insulations and wrapping the tank in it. 

Nomad

It was mentioned somewhere that if it's just slightly low you can just add some distiller water.

mawebb

As per the manual:

Regularly check the heating system fluid level in the expansion tank. The tank has markings on the side to indicate the maximum and minimum level for the fluid (See Figure 7). The fluid level should be about 0.5 inches (1cm) above the minimum indicator in a cold tank. Please see directions below for filling the heating system.

The heating system must be filled with a mixture of water and glycol. Use only high quality ready-mixed glycol (with inhibitor) intended for use in aluminum heating systems. The glycol must carry the label GRAS (generally recog- nized as safe). Please contact Alde for a list of approved glycol suppliers.

If you are using concentrated glycol, the mixture should consist of 60% distilled water and 40% glycol. If the heat- ing system will be exposed to temperatures below -15°F (-25°C) the glycol content must be increased, but not to more than 50%.

Any vessels used for the glycol must be spotlessly clean, and the pipes in the heating system must be free of con- tamination. This will prevent the growth of bacteria in the system. 

mawebb

Glad to hear you got it sorted out.  The Alde system is great, but definitely more complex to maintain that the simple propane fired forced air systems. 

jehdfd

I know this is late...but I wanted to thank RTab for the circulation pump advice. We just returned from our first trip where we needed the heater and it kept us up until we turned it off. It gurgled and made so much noise. The pump was set to five also. I turned it down and now it's nice and quiet and it works great. Thank you!

Nomad

If I recall my discussion with the factory last November, the factory normally sets it at two. If you're not getting enough heat, you can turn it up.

KBecker57

My brand new T@B is gurgling in the expansion tank. Wakes me up. My circulating pump does not have a little red adjustment knob so if the problem is caused by the pump set too high, how do I turn it down? And if it's air in the system that's causing the problem, it appears to have an automatic bleeder (round brass thing) so there's nothing to bleed. What do I do?

Tabaz

I had the same problem.  I checked the reservoir level and found it at the minimum level.  Added some 50/50 mix of Prestone LowTox anti-freeze to between the minimum and maximum indicators.  Noise went away.  No need to bleed the system.  Hope this helps.

Tabaz

The circulating pump hums when it kicks on.  The noise level can be minimized by lowering the pump setting to 1.5.

Nomad

KBecker57 - First, you'll never get rid of the gurgling sound. It's not really air, it's more just the wave motion of the fluid entering into the expansion tank from what I could tell. Drove me crazy for a week because it was a noise I wasn't used to. Then my brain started filtering it out like all the other extraneous noises our ears pick up all day/night. So, my recommendation is to give your brain a little time to rate it as a non-threatening pattern. But, you could insulate around it if you can't wait :-)
As far as the little red dial - I had to use a mirror to find the thing - it definetly wasn't obvious and easy to spot. Mine's just a quarter inch or so in diameter.

Tabaz

I agree with PXLated - I needed a small mirror to find the pump face with the dial adjustment.  However, the gurgling noise went away immediately after adding the extra fluid.  Like PXLated, I've learned to live with the quiet pump hum and be thankful for the awesome heat it helps puts out.  KBecker57 - please consider adding ChrisK's rear deck heat vents for even more warmth in the cabin.

Nomad

My gurgle's still there even with proper glycol level - But can't recall what I set the red dial at a year ago.

KyBawpaw

I hope that Alde system runs good for you guys. My T@B has an Atwood propane furnace but I guess it pulls more amps than the Alde? Hence the Alde popularity? From what I read here Alde seems very complicated and maybe finicky.  I have only a shore power capable hot water heater. A 2 gallon electric. The Atwood runs and heats great but I've only used it once at an RV park while on shore electric so the battery was on charge. Did get into the upper 20s that night. My ceramic heater broke earlier that night when I dropped it (imagine that). I've since got a new one. I bought a vinyl shower bag to fill with stove heated water to shower with should a boondock situation require it. I don't have anything onboard that "gurgle's" though. Just the wife when she's sleeping <smile>.

Nomad

KyBawpaw...Alde-finicky/complicated - Not at all. Mine just ticks right along on a daily basis. Wonderful little system that takes very little battery juice to operate. It was one of the main reasons I bought a T@B.
The forums can distort ones impression because this is where you come if you do have a problem.

Tabaz

KyBawpaw - I second PXL's comments.  I love the Alde.  Much quieter than the forced air units in RV's I rented prior to buying the Tab.  There is a slight learning curve with the manual control panel (two lighting bolts vs. one?), but once figured out, the system is a dream.

Ratkity

I have to echo PXL's comment about forums having a tendency to magnify a problem. My Alde has been working flawlessly, even when the pump was at 5 (I turned it down to 2). I didn't notice any major gurgling even at 5, but I've lived with radiant heat in the house for 15 yrs and may just tune that out naturally. I've learned so much from the people here. I can't say enough good things about this forum and our creative peeps and our diligent mods.

ChanW

I love the Alde too, but it will require a little bit more maintenance than a forced air would. ie: replacing the glycol every two years or so. Definitely worth the trouble though.

I think the biggest overall problem with the Alde has been folks understanding the control panel. It's European, and uses those European symbols that we may not be used to. A good instruction pamphlet would help.

Otherwise, the complications are no different from other water systems, I think.

Nomad

ChanW - But with forced air don't you need to change filters every so often? Maintenance no matter what system.

When I got my T@B, read (somewhere) that the controls should be - two bolts, propane (flame), water/heat or water - has been set that way for 15 months and just purrs along - didn't find the settings all that confusing. I can see where the first slider could be but I just followed that original advice and no problems. Of course this is all dry camping. Can count on my hands the number of times I've had hookups.

ChanW

PXL, I didn't have any problem with the controls either, and they were clarified more for me when I read the various instructions that Alde has put together, but I'm a geek, and I like decoding instructions.

The "problem" I mentioned, with the control panel being confusing to some, is shown by the number of discussions, people asking questions, and hashing it over and over, on the forums. Says to me that the control panel isn't exactly intuitive for "normal" folks.

And 'two lightning bolts' is no different from 'one lightning bolt' on your settings. That makes sense... B-)

Nomad

ChanW - As I mentioned, I read it in a thread here and just went with the settings it declared - no fuss, no muss :-)

KBecker57

Thank you for the responses to my gurgling problem. I added some distilled water to bring it up to the max line a few weeks ago but just tested it last night and it still gurgles and wakes me up. I sleep very soundly and would generally get used to some noise. I'm thinking the solution is to replace the circulating pump with the type that has an adjustment knob. Thoughts? Does anyone know why some T@Bs have the adjustment knob and some don't? Our T@B was manufactured a few months ago.