Vaillant ecoTEC pro 28 combi Boiler advice?

bery_451

Currently there's 7 radiators being powered by this boiler. Is the boiler powerful enough to power a further 6 radiators considering a two storey side extension?

What is the difference between a boiler Plume and boiler Flue?

Another question is once the new windows are installed on the side extension the boiler needs to be moved or the flue/plume needs to be temporary extended, the pics below will hopefully give an idea of the situation:


http://imgur.com/a/sPFy9


However as a temporary measure we like to get the boiler flue/plume extended once the new windows are installed on the side extension and later on in the project move the boiler or get a new boiler if current one is not powerful enough.

Regarding boiler flue/plume extension what are the current gas safe regulations regarding this? What is the maximum distance it is allowed for this flue/plume extension? Am I allowed to extend the flue/plume to the window at the other side as seen in the pic?

Alex1983

As a rough guess, without doing all the full heat loss calculations I've always worked on the basis of 1.5kw per rad and 3kw for hot water. On that basis your calculation would work out at 22.5kw so should just about run it. I'm not sure if the vaillant is the same as the Worcester as in the 28kw combi is really 28kw when doing hot wate and 24kw for heating if it is your really pushing the boiler to the limit, also if your putting more bathrooms or en suite then a combi is really 1 tap operations.

A plume kit is like a snorkel that's fitted to the flue to take poc's away from openings and areas that will cause a nuisance.

The boiler could have the flue extended as long as the manufacturers allow it to travel the distance you want it to go, a 1m flue extension will probably cost around 50-100 each and the flue will need supporting every meter on its route, it will also need to continually rise approx 50mm per 1m.

Alex1983

I've just had a look at the installation instructions for your boiler the flue can go a max of 8m including 1 elbow, for each additional elbow req the max flue length will reduce by a meter.

The boiler has a maximum central heating of 26kw, I still think the boiler would do it but you'll be pushing it right to its limit.

bery_451

Ok much appreciated for your valuable advice there.

Ok from my understanding from your replies please correct me if im wrong is:

- A plume kit is fitted at the end of the flue where the smoke comes out?

- The flue extension can either be horizontal or vertical? For horizontal flues it requires a 50mm increase in height for every 1m like zig zag pattern and wall bracket supports every 1m correct?

- Max is 8m for horizontal or vertical? And for every elbow used I have to subtract 1m from the max permitted?

southcoastrgi

That boiler shouldn't be in operation now inside that extension windows or not

southcoastrgi

bery_451 wrote: »

Ok much appreciated for your valuable advice there.

Ok from my understanding from your replies please correct me if im wrong is:

- A plume kit is fitted at the end of the flue where the smoke comes out?

- The flue extension can either be horizontal or vertical? For horizontal flues it requires a 50mm increase in height for every 1m like zig zag pattern and wall bracket supports every 1m correct?

- Max is 8m for horizontal or vertical? And for every elbow used I have to subtract 1m from the max permitted?

Your gas safe registered engineer will know all these answers you can't extend the flue yourself, you have already put your family at risk with leaving that boiler working, no one is going to tell you how to kill them

bery_451

Building inspector said boiler should be relocated or flue extended. Most feasible option for us now is getting the flue extended temporary until the plasterboards are up.

Furts

bery_451 wrote: »

Building inspector said boiler should be relocated or flue extended. Most feasible option for us now is getting the flue extended temporary until the plasterboards are up.

I am guessing the Building Inspector took one look at the new walls, a quick look at the state of the site and thought this is all a lost cause. The state of the existing boiler flue simply matches everything else.

bris

Furts wrote: »

I am guessing the Building Inspector took one look at the new walls, a quick look at the state of the site and thought this is all a lost cause. The state of the existing boiler flue simply matches everything else.

What are you on about? The building inspector knows a flue can't terminate inside the extension so his advice is to move it to another outside wall or extend the flue through the extension to terminate outside.


This comes with problems concerning the size of the flue run and inspection hatches that needed to be placed along it's length. Although a suttle pipe box can sort that out easy enough.


The plum kit is needed when the flue terminates near a window, vent etc where the clearances aren't met, it simply extents the termination to a point where there is no danger of the CO blowing back into the house.


Bigger houses use system boilers with unvented cylinders for hot water reasons not heating ones. Even larger 40Kw or more combi boiler struggle with hot water demand when there are 2 or more bathrooms in play, they struggle to heat 2 taps at once let alone fill a bath when someone is taking a shower.


Where as your 28kw combi will heat the radiators no problem, it will still struggle if you add any more hot water demands to the house.

bery_451

Ok with 2 bathrooms at play what Gas combi boiler output is recommended?

Also I come across this free boiler guide on these website forums:

http://www.moneysavingexpert.com/utilities/free-cavity-loft-insulation

Do they supply the new boiler only for free or do they also get involved with the copper pipeworks re-routing for free as well?

Alex1983

A combi boiler is designed to give hot water to 1 tap at a time, you could put a big boiler in that has a high dhw flow rate and you may get away with it but it's a poor design. You also need to know what pressure/flow rate you currently have. In a ideal world you should be looking at a system boiler with unvented hot water.

Not sure on free boilers, when the scheme was running a few years back no boiler was replaced if you currently had a A rated appliance, which you have. Not sure if that is still the case.