Truma heating problems.... Or is it me?

[BigDean]

Hi all,

We have had our first van for over a year now and are still trying to work out if certain niggles are "just the way it is" or if we have a problem.

We have the Truma Combi 4E system which on the whole works well. What is annoying is on a morning when we want to heat the van up and have hot water. It seems the 2 are mutually exclusive.

If I set the heating to 20 degrees and the water to "hot", then it achieves neither. It will get to 15 degrees heat and 40 degrees water. If I just put either on independently of the other, it works as it should.

Is this system really not capable of providing heat to both? Surely the system specified should be able to perform this task?

I have tried on electric and gas with the same results. It is also not because we are in the middle of winter. Currently in Europe with lovely weather.

This is the reply from Truma support: "If you have water and heating no at the same time then it will prioritise heating always unless you press boost". Doesn't really help.

Any shared experiences very welcome!

Thanks
Dean

 

[MikeD]

Are you running it on just EHU?

The boiler basically only runs at around 1/2 power. You probably will need to run it on gas+electric when you require a period of higher output.

The fan will speed up considerably when you do.

 

[BigDean]

Thanks Mike, thats good info. I will try that tomorrow morning!

All the best
Dean

 

[Zigisla]

As stated above, the EHU option isn't anywhere near as powerfull as the Gas option, but never the less, it will still prioratise heating over water. The water is getting hot because the heater furnace is hot. We set both to come on in the morning, then when the chill has gone and temp warm, but not fully up to temp, we get up and switch water on to boost and when that is up to temp, the heating kicks back in. Another check is ensure you have set the EHU setting to Elec 2. Best setting is as @MikeD says, Gas and Elec 2

 

[BigDean]

Thanks for that. Will report back tomorrow!

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[DDJC]

I got an electrician to install a 16 amp ehu socket at home so I can pre-cool the fridge, frost protection etc. We use the Combi 6E. The settings it has are similar to the 4E.

I've been experimenting over the winter and found that while gas-and-electric is the quickest, it is also the more economical, in that the amount of electricity used is less than is used when on electricity only, on eco or hot or boost or any other setting.

Or at least it used to be. The recent (ridiculous) price hikes of the B & Q lightweight propane cylinder refills has changed the balance a bit and next winter, I might go to electricity only. The other issue is that my house doesn't run out of electricity but Mrs DDJC would be rather terse if she wanted to nip off for a weekend and we had emptied the gas.

 

[Lenny HB]

It's not you it's the stupid heater, the older 4002/6002 were fine but the Combi 4 & 6 are a pain. We only have a gas Combi 6 principle is the same.

To start with don't ever bother using the 40° or now called Eco setting on the water. Water gets up to temp then the thermostat cuts out, it has a huge hysteresis and will not cut in again until water temp drops to 27° making it pretty useless.

Just hot water on it takes about 40 min to get to 60° (a lot longer than Truma say).

Heating + water it takes over an hour for the water to get to 60°.

Just heating on it takes well over 1½ hours to get the water to get hot.

When setting the hot water if you select "Boost" it will turn the heating off until the water is up to 62° (62? don't ask).

Armed with this info and a bit of logic, so what I do so I can get up in a warm van with hot water for a shower:-

I want the van warm at 8am and hot water for a shower:-
Set the timer to turn on at 7am & off whenever.
Set heating temp.
Set water to Hot.
Set " Boost"

Now set like this the boiler will light but only the water will be heated as it is on Boost, once the water is up to temp 40-45min the heating will turn on.
8am wake up to warm van & hot water.

 

[BigDean]

Thanks guys. I will practice..... at least it seems it isn’t faulty, just inadequate to provide dual max heat!

Thanks again
Dean

 

[BigDean]

Just thought I would report back. Set timer to 20 and hot/mix2 starting at 6:30. When we got up at 8 the heat was 20 and water at 50. So all happy.

Thanks for your help everyone.

Dean.