ANOTHER Alde Hot Water Thread

tombeaux

We have been heavy users for more than five years. Recently, we can’t get hot water for more than 30 seconds. It’s very hot, but then cools starts running and the hot doesn’t return.

I have the mixing valve all the way to max +. (Yes, I removed the screw and turned it past the stop). On the menu on my digital screen, I pressed the hot water selection so that the triangle is full dark. And yes, electric is set to max and propane is on.

This worked for us thru many navy showers for two people for years. And now it doesn’t.

The Alde kept us toasty last night when the outside temps dipped to near freezing, so it’s working.

Footnote: I recently drained (actually sucked with a shop vac) and refilled the Alde glycol. When it was empty I checked all the fittings, removed the corrosion and re-attached all the hoses using screw-type hose clamps. As I said, the Alde is heating and is full of new glycol.

tombeaux

Update - My wife, washing dishes at the moment, says hot water lasts closer to 15 seconds.

Binghi

The Alde glycol and hot water systems are independent. Have you recently opened the yellow pressure relief valves to add an air cushion to the hot water system? Or drained the hot water tank recently?

tombeaux

I opened it a couple of times this evening trying to troubleshoot, 5-10 seconds each time.

tombeaux

@Binghi - To clarify, I am opening the yellow valve 5-10 second, which partially drains the boiler. Should I be pressing down on the closed valve to let in air?

pthomas745

First: what position are your trailer valves in?  Camping season mode?  Winterizing Mode?  What position is your mixing valve in?  The "Air Cushion" is a red herring here.  It would have nothing to do with water delivery.

This is my 2017 in "Camping Season Mode."  Check these next. If #2, #3 or #4 are in the wrong position, the hot water will not be delivered properly. 

manyman297

Would air introduced into the glycol lines cause this? Let’s say there’s air in the line trapped near the boiler? What does the water temp on the Alde panel show?

Sharon_is_SAM

@tombeaux - go into the service menu after the Alde has been heating for a half hour - what is the temp?  

Are you on city water or using the pump?
I wonder if the mixing valve has failed?  

Is the Alde glycol pump set to Therm as opposed to Continuous?  You may have set it to continuous when you did the glycol exchange.

@manyman297 - his Alde is providing cabin heat, it appears to be working.  It should heat the water by default.

tombeaux

@Pthomas745 - Valves are all open except the hot and cold drains (like your photo).

tombeaux

@Sharon_is_SAM - Service menu shows heater temp and “sanitary temp” at 147 degrees.

tombeaux

I’m wondering if my mixing valve has failed?? When we turned on COLD water at the sink last night it  came out very hot for a few seconds. It has done that several times.

Mickerly

Check the valves in the exterior shower are closed. If Open, the hot and cold will mix through the valve assembly. Then you have only moderately heated water.

Sharon_is_SAM

@tombeaux - is the pump set to Therm?

stepheng

Couple of thoughts.  Turn on the hot water. Is the hot water line to the mixing valve hot and output line of mixing valve cold?  If so, probably the mixing valve.  It's not uncommon for them to fail  - and they are designed to fail "cold" to prevent scalding.  Also, drain the hot water tank (after heating and make sure Alde is off) and see if all the water that drains out is hot.  If so, it's the mixing valve.  I had a 2018 T@B and was unable to find the replacement internal parts for the valve (its from Sweden) - you can replace internal mixing parts without removing the valve.  Might have to find a domestic one or order newer one on the later model T@Bs from NuCamp and re-plumb.

pthomas745

@tombeaux Just want to confirm your comment: the "Bypass" valve in the photo (#3) should be in the closed position.

pthomas745

There are "faulty mixing valve" threads for that style of mixing valve (LK 550).  In one comment, Verna mentioned taking the mixing valve and adjusting it across the full range of "mixing" and it solved here problem.  There are other ideas in this thread, too.

https://tab-rv.vanillacommunity.com/discussion/13729/lk-550-mixing-valve-faulty

This thread has another discussion, but mostly about "how to adjust".  On the second page, there is a schematic of the innards of the valve if this is something you want to take apart and look at.

https://tab-rv.vanillacommunity.com/discussion/2676/little-hot-water/p1

BrianZ

tombeaux said it was open!..
"Valves are all open except the hot and cold drains (like your photo)." 
Agree, bypass should be closed.  The change he described from hot to cold seems to also agree with bypass valve being incorrectly open. (But not like the photo)

tombeaux

@Sharon_is_SAM - Pump is on Therm.

tombeaux

Okay. I missed the Alde bypass that is supposed to be closed. I have closed it, but we are hooked up and on the road. Will post tonight or tomorrow after testing in this configuration. In the meantime, thank you for all your responses.

tombeaux

SUCCESS. It was the Alde by pass valve that I had open. We are boondocking on BLM land near Capitol Reef National Park and did two Navy-style showers  back-to-back tonight. Thanks to this community!!!  I relied on a faulty memory and will consult my cheat sheets from now on.