Alde 3000 Control Panel
Vikki Nagindas
A few days ago purchased a Bessacarr Cameo 625 caravan with the old Alde 3000 compact unit fitted.
Water pump was demonstrated and worked, hot water was there, all appeared to be in order, and all manuals were present to peruse at leisure.
It wasn't too cold at the time, so only on the following day was it noticed that blown heating wasn't coming on, thought it may just need a thermostatic tweak, but not the case.
All fuses have been checked and appear Okay.
There are two Sargent control panels above the caravan door sited next to the thermostatic controller, the one on the right has 4 buttons, 1KW, 2KW, gas flame and a circulation sign, initially a green light came on when the flame button was switched on, then the red light came on as well briefly before the green light went out.
There is now no lights illuminating when any buttons are switched on.
The remainder of the electrics in the caravan are functioning as they should.
The control panel shown on page 13 of the Alde compact 3000 operating instruction manual is something I cannot find anywhere, previous owner and on site techie have no knowledge as to it's whereabouts, or what is behind the problems being experienced.
If it is of any significance a new external water pump was fitted in Sept 2017 and the liklihood is that the caravan has seen little or no use since then.
I've chased this around for about a year now. I've got a fault finding chart and a multimeter but the trouble is, when I switch it off, then on again as I start checking various parts for functionality, it starts working again, giving no clue as to which bit is faulty.
The electric elements in the Alde unit are 1KW and 2KW. You have confirmed that both work and do not trip the system. So its not an earth fault. By trip do you mean the vans RCD trips or just the Alde system switching off?
It should be noted that not every Alde 3000 is fitted with 3 Kw capability. Some only had a 1 Kw element backed up with a second 1 Kw element (instead of the 2 Kw). It can be verified by the code number on the boiler.
I would guess that you have a fault on the Printed Circuit Board which is causing this (and under the circumstances, it is only a guess). If you contact Graham Cutmore, he is a genuinely nice chap and might offer a pointer or two so you can fix it yourself. He will know if this is possible or not by asking the right questions.
The parts for these boilers are not cheap so I would take the van to an expert for a straight fix (as opposed to buying various bits until you hit on the right one). I have dealt with Graham for parts and repaired the boiler myself. He has no problem with this and even posted the parts BEFORE my cheque reached him.
Graham Cutmore suggests it is one of the relays on the main PCB that is failing - since it works on 1kW and 2kW mode but not on 3kW - and 3 kW is obtained by switching both 1 and 2kW elements into circuit. It's probable that the elements are OK and there are no thermal trips as such, just the relays, so it is likely a relay is failing when attempting to switch both elements into circuit for full power. It appears the elements themselves very rarely fail.
I had just the same problem as you but if you are the least bit mechanical - bodgery ;-) minded, as I am, I bought a recycled 12volt motor from Proops Brothers, complete with speed controller and 'fitted' it in - with (Clive) a nod in the direction of artful bodgery. The original is connected to the propeller shaft by a rubber sleeve, so easy enough to mod. The bottom bearing that often wears and causes the problem is a bit of nylon mounted in a rubber web and the use of a small lathe, or even a drill press and careful use of small sized drills bodges - sorry - repairs that one quite nicely. It's run for 6 months so far and at about 3.50 for 5 assorted motors, I'll try a few more times at that one before I give up and buy an original.
Thanks for that information about a new circulating pump motor. My problem is that I retired and joined a few motorhome forums. This means that I seem to have very little spare time these days. :D I still have the old one and will look into it. The new one has a beefed up motor. The old one was 32 mm diameter and the new one is 40 mm. It has performed perfectly for the last two years.
On the side of the boiler is a brass bleed valve. It is a pretty poor bit of kit and does not work effectively anyway. Mine started leaking fluid and this very quickly stops the heating working on low level fluid in the header tank. After a couple of attempts at repairing it, I devised a cunning way around the problem. This valve works like a steam trap in reverse, ie allowing air out without losing any fluid. I went to a pet shop and bought the one way valve used in fish tanks (for aeration). I fitted it after the bleed valve but the wrong way round, to prevent air loss. It only cost me a couple of quid and there has been no fluid loss and my system has never needed bleeding since.
Night Mode is set as before but we also use Day Mode. We set Day Mode to 50 F (10 C) to keep off the chill, starting at 09:00 when we leave, ending 15:00 when we get back. In the times between Day and Night Mode, the desired temperature reverts to 72 F (22 C).
The heating system must be filled with a mixture of water and glycol. Use only high quality ready-mixed glycol (with inhibitor) intended for aluminum heating systems. The heat transfer medium must be Propylene glycol based boiler antifreeze. The antifreeze must meet FDA (GRAS) standards or be non-toxic fluid having a toxicity rating or class of 1, as listed in Clinical Toxicology of Commercial Products, 5th ed.
If you are using concentrated glycol, the mixture should consist of 60% distilled water and 40% glycol. If the heating system will be exposed to temperatures below -15 F (-25 C), the glycol content must be increased but not to more than 50%.
When the liquid is cold, the level in a system of normal size should be about 0.5 inch (1 cm) above MIN. The bigger the heating system, the more the liquid expands and so the level should be lower when the system is cold.
For manual filling, remove the nut from the tank. Slowly pour the glycol mixture into the tank. Bleed the heating system and top up with more liquid if the level has fallen after bleeding. Bleed a newly filled heating system regularly during the first days the heating system is in operation.
Some installations are covered by regulations that also require thermostatic mixer valves to be fitted, to mix the hot water down to non-scalding temperature before the outlet. In the UK, touring caravans and motorhomes built for sale to end customers who are private individuals, are not required to fit thermostatic mixer valves.
The boiler is so ingeniously designed that in the first instance it selects the immersion heaters as primary heat source if 120 V is connected to the vehicle and if the immersion heaters are activated on the control panel. If this is not enough, the LPG burner starts automatically (if this is activated in the control panel).
Electricity is often cheapest, so this heating option is the cheapest one.