Do I need to drain old Alde glycol before adding new?

Seja

Hi new friends, we just got this Little Guy and discovered the heat wasn't working / the Alde system had little to no glycol in it. I went through past forums here and my husband & I decided we could re-fill it ourselves after finding the holding tank. I was reading on Alde's FAQ site that you should not mix two different types of glycol. Should I find the lower drain and drain whatever is in there out first or have you guys added to what's there safely? We don't know what type of glycol was used previously but the tank had barely any in it and opening the bleeder valve just gave out air. 

Sharon_is_SAM

Don’t run the Alde without/or low glycol as it can damage the unit.  Alde/nuCamp recommends Century Transfer fluid - available on Amazon and elsewhere.  If you don’t have much history on the trailer, it may be wise to drain and refill as it is recommended to be changed about every 2 years.  Do a search on draining the glycol.  Maybe @ScottG will chime in☺️

Seja

Thanks @Sharon_is_SAM! After some further digging, looks like there is a kink in the hose going into the expansion tank... have you seen that on the forum before? It's almost as if the tubing is slightly too long. I was able to drain all the glycol and will work on filling tomorrow. Appreciate your quick response. 

MuttonChops

Not an expert here butttt will comment.

A]
Using the Drain Plug will not 100% drain the system.  Alde has a special tool/pump attachment that will 100% drain the system.

At one time Alde USA would loan the tool/pump to owners.  Don't know if that policy has changed with the increase of Alde installations or their service departments combination with Truma.

Do get the impression from various thread posts that most folks (and maybe NüCamp) do not use the special tool/pump.  That is, they drain what they can then allow any remaining older and new antifreeze to mix.

B]
Believe the Do Not Mix antifreeze has to do with mixing antifreeze chemistry (types) not specific brands. For North America Alde uses a 'pet safe' or sometimes called food grade chemistry. In short if the heat exchanger gets a leak your hot water won't become poisonous.  Alde manual provides details on required antifreeze chemistry.

In addition to being 'pet safe' it must be approved for use with Aluminum!

As noted by @Sharon_is_SAM the Century product is recommended.  Expect this is the case because it is the correct chemistry and it is already in a 50:50 ratio with water so you can just use as is.

Peak brand Sierra is a 'pet safe' product (available in many auto supply stores) that meets the Alde requires.  However you must mix with distilled water to create a 50:50 mix.

Seja

@MuttonChops thanks for the reply; we ended up getting the Peak brand from Napa earlier today. Looks like most of the fluid drained out when we pulled the drain plug and even more once I removed that kink that was in the line I was able to leave a message for Alde technical support but haven't heard back yet; I will ask them about that pump just for fun but sounds like it's OK to mix "old" and "new". Appreciate it!!