12 volt timer

[CampinGazz]

I bought an eberspacher 7 day timer for use with my proposed heating system the other day, got it cheap thankfully (£36) and want it for the diagnostic functions more than owt else.

 

But from the very vauge instructions it seems it's either 3 times in the next 24 hours, or one time in the next 7 days, it seems to indicate that it clears the memory after it's run the time period.

 

I want to use it to have 3 times to power the heater up per day, every day, this will put power on the heater start up wire which goes through a thermostat on the calorifier, hence if the stat is closed and the timer is on, the eber starts up and heats the calorifier untill the stat opens when it's upto temp.

 

heating will be just a simple on off switch, on when i want heating and let the thermostatic valves on the rads take care of the temp.

 

Can anyone confirm or deny how the eberspacher 7 day timer works? i.e. can i set up 3 times for it to start up during the day... say 8am, 12 pm, and 5 pm, set it to run for 20 minutes per on time, and it carries on doing that 8, 12 and 5 start up time every day intill the memories are canceled?

or does it just run a single memory then clear it which is how the instructions seem to indicate.

 

If it's the latter, then i need to get a 12 volt timer, i want a digital type, something like a central heating programmer, but one that runs on 12 volts not mains,

i have found a nice looking one, big display, 4 on and off times per day, 5/2 time periods, networked to work with suitable room stats and so on,

basicaly it'll do the job i want, but also do half a million other jobs i dont want, it's also £35, here it is if anyones interested

 

i really want something a bit simpler than that, and cheaper as it'll only be switching the hot water heating on and off and not hte central heating,

[GUMPY]

 

Can anyone confirm or deny how the eberspacher 7 day timer works? i.e. can i set up 3 times for it to start up during the day... say 8am, 12 pm, and 5 pm, set it to run for 20 minutes per on time, and it carries on doing that 8, 12 and 5 start up time every day intill the memories are canceled?

or does it just run a single memory then clear it which is how the instructions seem to indicate.

 

Running ant diesel fired boiler this way is a guaranteed way of making it coke up.

The only way to do it is to set it to run for at least 2 hours with NO thermostat so that it will heat the water then switch off.

A lot of calorifiers will not heat the water in 20mins there is not enough thermal transfer between the coil and the water. If this is the case you will also need a heat leak as the boiler will heat the water in the pipes and there will not be enough heat transfer into the calorifier so it will switch off before the water is hot

The way that mine is run is from 4am to 7am, which heats the water and heats the bathroom through the towel rail, which is the heat leak for the system. The calorifier is well lagged and I still have water hot enough to wash up in the evening.

However if using the washing machine I switch the heater on manually so that I still have hot water after the machine has finished.

 

Running an eberspacer, mikuni, and webasto in short bursts or on a thermostat is a guaranteed way to make the coke up………

[CampinGazz]

ta for that,

 

only guessing at the times, the water will already be hot drom driving and the engine heating the calorifier, so the eber will just be keeping it warm,

 

it's only a little 20 litre calorifier too.

 

I always thought the reason for the after glow on the heaters was to prefent coking, but i guess as long as it dosent coke up in a day, i can live with taking it appart every so often to clear it out,

i'll be running it on parafin anyway, which is supposedly much cleaner burning, with a bit less heat output,

 

90% of the time the central heating will be running anyway, except for the hottest summer nights my GF complains of being cold, so we'd have the heating running at night at least, and the way i'll wire it is that when hot water is needed whilst the heatings running, it'll start the 2nd water pump up to supply the calorifier whilst keeping the heating going,

 

i just need to find out exactly how the eberspacher 7 day timer works, if i can set 3 on times a day, and have it repeat them automaticaly every day untill it's told otherwise, then the timer i have is fine, otherwise i'll have to get a seperate 12 volt timer to do what i want, and keep the eber timer for it's fault code retreval feature.

[Yamanx]

http://www.farnellinone.co.uk

 

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