truma combi boiler replacement with 2 seperate units, what options?

karmaan

im looking at an option of installing a gas water heater and seperate gas blow heater in my 96 hymer.
lots of stuff available, not sure what to chose. Budget of around a grand.
i have been quoted 2,700€ plus fitting for a new combi replacement.
My old one sat on its end over the wheel arch in the wardrobe.( before it was nicked!)
any suggestions welcome
t

crabbypaddy

If you're thinking about a domestic propane water heater beware theres lots of sheap chinese stuff about thats not room sealed would be very dangerous.

Would you consider diesel, for water and heat you could get a webasto hydronic, plus plump, plus heater/fan matrix from a ford galaxy in the scrap yard for small money. You'd have to add a calorifier with safety valve and expansion vessel for hot water. Using the engine coolant as in the galaxy you'd have the option of free water heating when driving and even preheating the engine in winter.

Calorifiers show up used on adverts/ebay from time to time for around €100 so if you're not in a rush could be a very cheap setup and very easy/ cheap to repair in the future.

http://www.surejust.co.uk/calorifiers

Propex is the most popular diy gas blown air heater, you can get them for £150-£250 used on ebay should be loads of diy guides on t4 forum and the like.

karmaan

Thats interesting, definitely worth thinking about
is it a big job to retro fit?

crabbypaddy

karmaan wrote: »

Thats interesting, definitely worth thinking about
is it a big job to retro fit?

The galaxy has all the bits you need to make hot water, hydronic unit, water pipes, diesel pump, fuel line, 12v circulation pump. That can all live under the vehicle. Calorifier, and expansion vessel might even fit undefloor depending on the space but would probably need protection.

You'd need to install a standpipe in the diesel tank or a plastic fuel tank if you prefer to use farm diesel so save some moolah.

Once you're making hot water you need a header tank, you could probably use the galaxy expansion vessel and calorifier and plumb it in.


This show how the electrical surecal calorifier is installed in a motorhome:
http://www.surejust.co.uk/surecal-12v240v-motorhome-water-heater-calorifier-installation-instructions

Was just thinking the circulation pump may be an issue depending on size of your battery bank, if you have solar and how long you're off hookup etc. Truma is only 1 watt when heating.

Hydronic going full tilt - 5000w is 37w at 2400w its only 10w.

Truma is only 1500w though so its going to be on a lot longer to heat the same amount of water.

Hydronic also heats to 85C which could be scalding so you'd want to use a cylinder stat at the calorifier return to turn it off at 65 or fit a thermostatic valve like on the surecal calorifiers I linked to earlier.

karmaan

Paddy
Great info thanks, looks like a powerful piece of kit, its not something id fit myself, and there's a good bit of work in it.
Do you or anyone else know anyone that would fit it? (better still supply and fit)
Preferably near enough to Dublin.

crabbypaddy

karmaan wrote: »

Paddy
Great info thanks, looks like a powerful piece of kit, its not something id fit myself, and there's a good bit of work in it.
Do you or anyone else know anyone that would fit it? (better still supply and fit)
Preferably near enough to Dublin.

They'd be on a lot of boats, so a boat yard might be your best bet but then any savings could quickly evaporate.

karmaan

Paddy
stroke of luck today, got a second hand matching boiler, took out the vessel, so going to get it sandblasted and resprayed.
whats the best paint to use?
id be happy to get 2 years out of it
Thanks for all the advice
t

crabbypaddy

karmaan wrote: »

Paddy
stroke of luck today, got a second hand matching boiler, took out the vessel, so going to get it sandblasted and resprayed.
whats the best paint to use?
id be happy to get 2 years out of it
Thanks for all the advice
t

Not sure for a normal boiler theres no direct contact so you could use something old fashioned like apexior 1 (used to be made in malahide) which is basically bitumen and carbon not sure if it would be approved for direct contact you'd may want something for potable water and I would say most of those won't do hot water immersion.

This 3m one is to be good to 60C immersion http://www.parkerjames.co.uk/3M-scotchkote-epoxy-coating-162PWX-blue?search=162pwx&category_id=0

I found these guys were super helpful whenI was looking for oddball intumescent coatings, might be worth asking them.

http://www.paintshop.ie/Steel-Protection.aspx

crabbypaddy

Forgot to say for aluminium you may need to etch with phosphoric acid before it will take any coating.