Vaillant Ecotec 30 Pro heat problems
- Thread starter Mike13
- Start date
Sponsored Links
You might also check D.005, the boiler flow temperature target value.
If the actual flow temperature d.40 exceeds this by 5C then the burner will trip and then refire after the recycle time has elapsed but if so, then S.08 should be displayed.
The readings above give flow/return dTs of 7C, 34C & 23C, if the dT exceeds 30C then the burner will again trip but not sure what parameters it flags.
A very high dT will normally occur during the first minute or so of firing up so after you establish the flow target temperature, monitor d40&d.41 closely from fire up and for another few minutes.
If the actual flow temperature d.40 exceeds this by 5C then the burner will trip and then refire after the recycle time has elapsed but if so, then S.08 should be displayed.
The readings above give flow/return dTs of 7C, 34C & 23C, if the dT exceeds 30C then the burner will again trip but not sure what parameters it flags.
A very high dT will normally occur during the first minute or so of firing up so after you establish the flow target temperature, monitor d40&d.41 closely from fire up and for another few minutes.
Hmm, a D.005 of 56C, so the 66C seen has tripped the overtemperature, something must be stopping the flow, I guess I need to pull out the pump and diverter valve again to see what is up inside there. I need some more inhibitor before I do that though, as I have used up what was left over from the initial fill.
Sponsored Links
well it is a combi, and up until I replaced the diverter valve that had sprung a leak it had been working ok. At that point the only bit I took off was the valve, nothing else was touched.
except, i did take out the filter and see it was almost spotless. (an Adey ) a pain to tighten up without leaking I found, but I use plenty of silicone grease on the o ring and thread, that seems to help.
except, i did take out the filter and see it was almost spotless. (an Adey ) a pain to tighten up without leaking I found, but I use plenty of silicone grease on the o ring and thread, that seems to help.
You can add inhibitor via one of the rads, later, once you have sorted out the problems.
You might check the boiler output on DHW, set the DHW temperature to max, 65C, via D.006?? then open a HW tap(s) to give 65C or close to it, you can measure it with a household thermometer but it may be displayed in the d parameters, then measure the flow rate by letting the HW run into a container for exactly 30 secs, X 2 to give the flowrate in LPM. You should get, with a 30kw boiler, a flow rate of 7.8LPM at 65C from a (mine) mains temp of 10C.
Also check D.014, the target pump speed setting and D.015, the actual pump speed. Do this on both CH and DHW.
You might also reduce D.000 to say 10kw to see if the boiler remains running at this CH partial load.
You might check the boiler output on DHW, set the DHW temperature to max, 65C, via D.006?? then open a HW tap(s) to give 65C or close to it, you can measure it with a household thermometer but it may be displayed in the d parameters, then measure the flow rate by letting the HW run into a container for exactly 30 secs, X 2 to give the flowrate in LPM. You should get, with a 30kw boiler, a flow rate of 7.8LPM at 65C from a (mine) mains temp of 10C.
Also check D.014, the target pump speed setting and D.015, the actual pump speed. Do this on both CH and DHW.
You might also reduce D.000 to say 10kw to see if the boiler remains running at this CH partial load.
Last edited:
Well I went to look at D.014 and D.015, D.014 was 0 and D.015 was 15% then 47%, and then next time I looked d.015 was 100% while heating was supposed to be running, we have a demand temp on thermostat of 28C to keep it running and an actual of 20.5 to 21.0 with auxiliary gas heating to keep house warmer. will measure the HW later as I have some jobs to do first.
D.014 position 0 = Auto, the pump will ramp up and down depending on boiler output, it can also be changed to "manual", may suggest this later after you have done the HW test.
I would suggest changing D.000 (partial load setting) to say 8kw to see if the boiler can run continuously at this range rated output.
How may rads on your system? any UFH?
I would suggest changing D.000 (partial load setting) to say 8kw to see if the boiler can run continuously at this range rated output.
How may rads on your system? any UFH?
Well I had enough of the system misbehaving, so as the diverter valve was the only bit that got changed, I took it out for a good look at it and found a bit of scale had dislodged from somewhere else in the system. It was a large curved bit that got stuck in the passage where the brass screw protrudes, to me that is an indicator that the system needs a good clean for a bit.
Any recommendations for a system cleaner I should circulate round for a bit?
Any recommendations for a system cleaner I should circulate round for a bit?
Fraid not, have no experience with chemical cleaning but if your magnetic filter doesn't also have a particulate filter then suggest installing one that has. These boilers have a internal bypass so maybe removing this to have a look for any bits of scale, these come set to 2.5M which I think is far too low for most CH systems but can be adjusted to a max of 3.5M, see page 24.
Is the boiler working OK now since removing the bit of scale?.
Is the boiler working OK now since removing the bit of scale?.
Not yet, I went out to get some cleaner from toolstation this afternoon. The diverter valve was fully cleaned before I put it into the system, so the scale has come from other pipework, I suspect the bit I found would not by itself have caused this problem, but it does tell me scale has built up elsewhere. So I will circulate some cleaner around the pipes for a bit and see if it starts behaving.
Does a Vaillant have any aluminium in it? some of the cleaners have to be washed out after only 3 hours if there is.
Does a Vaillant have any aluminium in it? some of the cleaners have to be washed out after only 3 hours if there is.
Don't know but ensure to flush out the system repeatedly as there are some horror stories of gases being generated due to lack of proper flushing after a chemical clean.
It is still at the stage of blocking up then pumping properly again, so it needs some more hours. I may add some citric acid if it is still misbehaving in the morning. I added a whole bottle that says enough for 16 rads, and I only have 12.
The system has had a power flush, but the boiler is still bad, there are knocks and bangs while it is running now.
Currently been drained and a whole bottle of adey cleaner added, still not any better.
I have set the pump to run at 100% and not modulate until the system is able to not keep kicking back to timeout after an S.7 event. I have also set the pump to 12Kw for now to try and give it more of a chance to not end up at S.7, but not sure if the 80% at startup is actually changed when you edit that setting?
Any ideas?
DIYnot Local
Staff member
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local
Sponsored Links
