New Heating System does not work!!!

[Caesar]

Hi Agile

The Boiler is a Vailliant Eco Tech PLus 428

After system had been installed Rad need bleeding every 3 to 4 days. The Magna Clean module sounds as if water is dripping into it! Is this normal and think Boiler engineer said he has bled it.

As far as I am aware there are no problem codes on the boiler though to be honest have not touched it from day it was installed!! Even engineer did not mention any fault codes. Are air lock easy to remove???

 

[mickyg]

no, the whole thing sounds like a disaster! its rare a vaillant engineer wouldn't downrate an oversized appliance, so I wouldn't be surprised if its already been done. I don't think this is something we will be able to help with from our keyboards, I think it needs a good engineer to go in and sort out the mess.

 

[mickyg]

sounds like a problem with the cold feed and open vent arrangement or a blockage from your most recent post. Likely the system didn't receive any kind of flushing.

 

[rojaca]

to quote a handy textbook 18-30 kw is normally in 28 primaries with dhw in 22mm and some heating requiring 28. Obviously dependant upon system design.
Would have thought lower return temperature for condensing blr would require more accurate pipesizing rather than less.
As someone else said earlier on in the key is having some flow and return temperatures.
Once again excuse my ignorance regarding blr. I'm presuming the blr is modulating down on the dhw and not cycling- cutting in and out. If this is the case we can assume the primary sizing is an irrelevance.

 

[mickyg]

your textbook is out of date. Its assuming a target tem diff of around 11C. Old SKool innit.
steamers require a temp diff of 15-20C (20 ideally but some get stroppy if they go over) so the pipe size can be downrated.

 

[Caesar]

Hi All

Assumig it is an airlock which is causing the Boiler to switch off before rads are hot enough, How can this air lock be removed?

When the installer instlled and commissioned the system instead of using the header tank to fill the system via the mains water flowing into it. The installer connected a hose from an outside tap and then filled the system until the header tank over flowed and water was expelled out of the over flow pipe is this normal? Would this cause the airlock?

 

[XKESTONMAN]

sunds like he back filled the system
which could suggest blocked cold feed.

 

[doitall]

sunds like he back filled the system
which could suggest blocked cold feed.

Either that or he made such a pigs ear of the installation that it wouldn't fill.

I would write to the guy and put it straight, either he gets it sorted or you get someone who fill at his expense.

Date it and keep a copy.

 

[mickyg]

When the installer instlled and commissioned the system instead of using the header tank to fill the system via the mains water flowing into it. The installer connected a hose from an outside tap and then filled the system until the header tank over flowed

sounds like a pro
I hope he was cheap!

 

[kevindgas]

do a quick check for us

press i
until D.0 appears
press i again
post the figure displayed as i suspect the heating hasn't been range rated

if it has then it should be around 16 to 19 if its higher then that will be part of the problem

press the flame with a line through button to return to normal

 

[D_Hailsham]

the House is 4 Bed Detached, the Boiler is a Valliant Eco Tec Plus 428. System has a three Port Diverter valve. Hot Water works fine.

]Boiler gets to about 70 Degrees and then shuts off as the Heat from the boiler is not dissipated quickly enough so the Valliant Boiler Engineer said who spent well over 2 hours checking the boiler!!

Boiler is considerably oversized.

Use the Boiler Sizing Wizard to find out what size boiler you really need.

I would guess about 15kw or less - assuming you don't live in a mud and wattle house with unglazed windows and no insulation. Then get the boiler range rated down to the required output.

 

[rojaca]

your textbook is out of date. Its assuming a target tem diff of around 11C. Old SKool innit.
steamers require a temp diff of 15-20C (20 ideally but some get stroppy if they go over) so the pipe size can be downrated.

Hi Mick. Your right. Have just done some calculations. Was aware of 20 degree differential req'd but was assuming that would want better flow rate. Not so
20 degree differential on 30 kw load would req' 0.357kg/s flow rate whilst 10 degree diff' actually requires 0.66kg/s.

 

[mickyg]

Hi Mick. Your right.

i try my best

 

[Caesar]

Hi Kevindgas

I did as you asked and the D.0 reading appears as 30

Is the normal for a Valiant Eco Tec Plus 428 heating 11 Rad, 4 bed detached house fully insulated both wall and loft?

Also Magnaclean cyclinder sounds as water is trickling throught it! Is this normal? It has been bled twice and on both ocassions air can be heard escaping and also towel rad needs bleeding every other day!

 

[kevplumb]

Hi Mick. Your right.

i try my best

ooh you modest git