About settings of a Vaillant EcoTEC 824 boiler

[Lucky Luke]

Hi, experts. Our boiler is a Vaillant sealed-system combi (an EcoTEC 824, about five and a half year old). It is now out of guarantee. There are only three radiators running off it, and they are all quite small (3ft 3inches, 2ft, and 16 inches long by 2ft high, respectively — the rest of the house is heated by gas-fires and electric heaters). When the installer set our system up, he said that, in view of its modest heating demands, he would adjust the boiler, to take this situation into account. All of the above is just background to two questions I should like to have answered.


Question 1) Because of intermittent ignition faults (which two engineers, on two separate call-outs, have not been able to cure), it has been necessary for me to switch off and restart the boiler, several times recently. The other day, thinking that it may cure the ignition failure problem, I re-set this boiler, by pressing and holding in the power button for one second, then re-starting it, as instructed. With respect to this, my question is — did this re-set also negate the boiler settings laid down by the installer, so that, now, the boiler does not take into account the modest heating demand? Or not?


Question 2) Yesterday, I felt there was a need to raise the DHW temperature, so out I went, with my instruction card, and pressed the relevant buttons. What I did not realise, until later, was that the display said, not DHW, but Target Flow Temperature. A day or so later, when looking through the manual, I realised my error. However, I could not remember exactly what the former Target Flow Temperature setting had been, so, later on, when trying to set things right, I reduced the Target Flow Temperature setting, without knowing whether I had set it back aright. I think the setting was left at about 58°. When I went out to check it, I could not find it!

Can anyone tell me what the Target Flow Temperature setting ought to be for this boiler, having in mind the fewness of our radiators? (I have spent far more than I can afford on engineers coming out to try to correct the ignition failures, without success. So, being a pensioner, I cannot afford to ask anyone to come out again.) Please advise me. Answers to both questions would be greatly appreciated.


With thanks in advance,

A.W.

 

[muggles]

What fault codes are you getting during these "ignition faults"? Your boiler will never have been able to properly take account of your modest heating demands...it simply isn't designed to run on such a small system. The target flow temperature should be as low as possible whilst still making the house warm, although in reality it's going to make bu99er all difference to efficiency on a system that size, whatever you do with it it'll cycle like Bradley Wiggins. This might be a root cause of your ignition issues though - the boiler has spent its life starting and stopping (cycling) far more often than it was ever designed to, so now it's getting a bit knackered.

 

[Lucky Luke]

What fault codes are you getting during these "ignition faults"?

Muggles, thanks very much for this important information. The fault codes are mostly F28, and sometimes F29.
A.W.

 

[Lucky Luke]

What fault codes are you getting during these "ignition faults"? Your boiler will never have been able to properly take account of your modest heating demands...it simply isn't designed to run on such a small system. The target flow temperature should be as low as possible whilst still making the house warm, although in reality it's going to make bu99er all difference to efficiency on a system that size, whatever you do with it it'll cycle like Bradley Wiggins. This might be a root cause of your ignition issues though - the boiler has spent its life starting and stopping (cycling) far more often than it was ever designed to, so now it's getting a bit knackered.

Muggles: I have no knowledge of what is good and bad, as regards central heating, so, I am not "answering back", like a naughty child to an adult. However, what you remark has me feeling very worried, so I feel compelled to point out the following facts.
1) In cold weather, although the rads make the rooms plenty warm enough, the target temperature is not reached for a long time (usually, it's about noon when the target has been reached and the flame symbol goes off the thermostat display). After that, it stays at target for most of the afternoon (except in bitterly cold weather). So, it does not seem to be cycling like mad.
2) I have two relatives that have central heating, but do not use all of the rads in their house. One of them is so poor that, mostly, she only runs the living-room rad, to avoid large heating bills. The rests are turned off. She has been in that property, with the same boiler, for about fourteen years (apparently, without any deterioration of the boiler). The other relative cannot stand having heated bedrooms (though she could well afford this). So, the only rads that she has on, in cold weather, are a smallish one in the hall, and two in her large, knocked-through living room (one at each end of the room). Again, she has no trouble with her boiler. I am hoping, desperately, that our boiler is not knackered, as you suggest, by our modest heating demand on it. Since, for what peace of mind I can gain, I need all the information/responses that can be obtained, any responses to the above reports would be very welcome.
With thanks in hopes of that,
A.W.

 

[ReganAndCarter]

If I were in your situation, I would take some of the money I was burning through by using gas fires and especially electric heaters - and invest it in extending the heating system. I would be making maximum use of the boiler, as it is by far the most cost effective way of heating a house. Spend now on new rads, then see the savings for years after.

 

[Lucky Luke]

If I were in your situation, I would take some of the money I was burning through by using gas fires and especially electric heaters - and invest it in extending the heating system.

I appreciate your comments, friend(s). However, we certainly don't want radiators in the bedrooms, as neither of us can sleep in a warm room. The electric heater there is hardly used, even in daylight hours. In our small living room, there is no place to put a radiator (apart from having the chimney breast knocked out, and putting a rad. on that wall — which would be very expensive, not to mention disruptive). Space for a rad, about 55 inches long, could be found in the dining-room. However, the height of radiator would be limited to about 18 inches, from its top to its baseline. Are there radiators as narrow in height, as that? The study is the size of a postage stamp, and its electric heater can be quickly switched on or off, unlike a radiator (In the time that I spend in that room, I frequently need to change the temperature according to changes that occur — heat from the computer being one cause). Therefore, I think that the maximum possible extension of the heating system would run to only one more radiator (size as stated). Do you think that just this would give the boiler a much easier time? If it would, I would consider doing that. Otherwise, we would be quite happy with the arrangement that we have (except for our concern about the boiler's unnatural workload).
A.W.

 

[ReganAndCarter]

If you're short of wall space, some tall rads start at 8" approx. in width, plus the extra width for valves. With thermostatic valves fitted, will be controllable. Heat up quicker than most types of electric heater too.

http://www.bestheating.com/milano-w...-column-radiator-1500mm-x-203mm-vertical.html

 

[Lucky Luke]

Thanks mate. I'm like a five-year-old where matters like this are concerned. It's all food for thought.
A.W.

 

[Lucky Luke]

If I were in your situation, I would... invest it in extending the heating system. I would be making maximum use of the boiler

Friends, I have been thinking about your advice. In view of what Andrew ("Muggles") said earlier, the very small demands made on this boiler are not doing it any good. Because of the particulars of our situation, we could only consider one more radiator. This would be in the dining room, where there is space for a double boiler about 40/42 inches wide and 24 inches high. Now, my question is: would the addition of such a boiler make a significant lessening of the abuse that the boiler seems to be suffering? Or would this not be enough to make the boiler "happy"? I should appreciate your considered opinion. Thanks in advance.
A.W.

 

[Lucky Luke]

Your boiler will never have been able to properly take account of your modest heating demands...it simply isn't designed to run on such a small system. although in reality it's going to make bu99er all difference to efficiency on a system that size, whatever you do with it it'll cycle like Bradley Wiggins. This might be a root cause of your ignition issues though - the boiler has spent its life starting and stopping (cycling) far more often than it was ever designed to, so now it's getting a bit knackered.

Andrew/Muggles: After your comments (which had me feeling scared rigid), I made more enquiries, as, because of what you said, I was considering going through the expense and upheaval of having another radiator installed. This is what I was told, by a heating engineer: Your boiler is a modulating boiler, which means it can run at a lower KW, depending on the demand. It would run perfectly happy with only 1 radiator. I am copying what was said to me, in case anyone else is made to feel concerned about their own Vallant EcoTEC Plus 824 boiler, if they too make only modest demands on it. Phew — the relief!
AA.W.