Vaillant ecotech 831 - Not up to the job?

[goon3r]

Ok - did as suggested. rated boiler and set to d.0 12 output. (was on d.0 24 before i changed btw)
closed all lockshields then turned downstairs rads one full turn and upstairs 2/3 all trv's fully opened.
result of this bearing in mind system only been on for 30mins...
- rads in through lounge and kitchen: cold at bottom mildly warm at top.
- the hallway rad where room stat is cold all over
- rad in bathroom & back bedroom too hot to touch
- rad in all other rooms upstairs warm at top and luke warm at bottom.

What now?

Sounds like thats the problem, wonder if the powerflush has blocked the manifold.

.....is this blockage possible?

 

[sambotc]

Get the installer/powerflusher back.

It's not working and was prior to there work. I'd be stripping down the manifolds and checking there not blocked up.

Sam

 

[goon3r]

installer coming back on saturday. fingers crossed. Thanks for your advice guys.

 

[Agile]

Dont panic!

On the too hot rads, close the lockshields and note how many turns.

If correctly set to just 2/3 turns the open to just 1/2 turn. Note these are fractions of a turn and NOT two to three turns!

On the totally cold rad open three turns.

On all the slightly warm rads open a full turn more.

Then report the results after 30-40 minutes.

Tony

 

[goon3r]

Dont panic!

On the too hot rads, close the lockshields and note how many turns.

If correctly set to just 2/3 turns the open to just 1/2 turn. Note these are fractions of a turn and NOT two to three turns!

On the totally cold rad open three turns.

On all the slightly warm rads open a full turn more.

Then report the results after 30-40 minutes.

Tony

Ok - will try this evening when i get in. Keep eyes out for feedback about 8pm.

Can I ask....changing the rating of boiler from 24 to 12 hasnt made any difference from what i can see? will doing this mean im using less gas, forcing it in condense mode therefore making boiler more efficient?

 

[mickyg]

Can I ask....changing the rating of boiler from 24 to 12 hasnt made any difference

no it won't

will doing this mean im using less gas, forcing it in condense mode therefore making boiler more efficient?

no it won't make any difference

 

[Agile]

It will be slightly more efficient but not a very significant difference.

I would suggest perhaps 2% but others will disagree.

Tony

 

[DP]

Tony wrote

So it needs range rating as well as balancing.

Sambotc wrote

The boiler fires on full for 5 seconds, the return temp is obviously high as the heating has been on all night. The boiler then drops right back to low and slowly ramps up again as it calculates what is necessary to match flow with output.

My system comprises three rads downstaris and four upstairs. Boiler is an Ecotec 832. Upastairs and downstairs are plumbed as S Plan. Boiler is not rangerated. Boiler has worked faultlessly.

Working on 'S 53' fault thrown by an Ecotec presently. Will hopefully post when I get to the bottom of the problem (if successful). In order to make sense of this fault, have purchased a twin display Testo temperature meter. Hope to carry out time/ temperature chart to get to bottom of this problem.

Although it has been suggested by the OP that the system has been balanced, fail to see how as circulation seems to the cause in this case. 10mm, 8mm even 6mm (now sitting in a bunker having said that) to rads cannot be taken as a flawed, if the length is appropriate to load. Have seen BIG combis fed by 15mm gas line (boiler just about sitting atop the gas meter)
OP is the pipe plastic or copper?

 

[goon3r]

If correctly set to just 2/3 turns the open to just 1/2 turn. Note these are fractions of a turn and NOT two to three turns!

On the totally cold rad open three turns.

On all the slightly warm rads open a full turn more.

Ok - not great news. can see whats happening here with tweaks. the two super hot rads upstairs are hot all other rads in entire house couldnt even be described as warm

Before changes all of upstairs was hot but this is hopeless. After Arsenal game will try tweaking some more - wish me luck

 

[sambotc]

You need to open 1 radiator at a time so the full force of the pump is trying to circulate that one radiator.

Turn all but 1 off to see if it works and pipework is OK. If it does, move onto the next and turn the first one off.

Once you verify all radiators work on there own, you can try and balance.

You know the downstairs work so skip them, just turn them straight off.

Sam

 

[wull67]

the faults you are describing are very similar to having a bye-pass that has not been set. is there an external bye-pass fitted

 

[Agile]

Thats a very good point! The rest of us have overlooked that.

As far as I am aware the boiler has a built in by-pass on the left of the pump.

He has advised that its a microbore system. Thats would have a higher flow resistance.

If the bypass has not been reset then most of the flow is probably returning through the bypass leaving insufficient head to give adequately circulation round the system.

This definately needs to be checked. Although the system seems to have severe balancing problems. Thats rather unusual as microbore is to a fair degree self balancing.

Tony

 

[sambotc]

the faults you are describing are very similar to having a bye-pass that has not been set. is there an external bye-pass fitted

Good thinking batman

Would have expected the installer to removed but not necessarily.

definitely worth a check

Sam

 

[transam]

Phew, read all the post's , circulation prob ' have had a couple of job's recently where a fixed rate boiler has been changed , for a modulating A rated condenser , & the rad's no longer get as hot , both on 8mm , custumer's were warned , they will be repiped !! what about a 2nd pump ?? just a thought ???

 

[goon3r]

the faults you are describing are very similar to having a bye-pass that has not been set. is there an external bye-pass fitted

Wull67....how can i (novice) check this? Do i have to ask the installer directly?

Microbore is 8mm btw, not 10 as i said earlier.

Also, DP - pipework is copper not plastic.