Update gravity central heating system to combi

Interesting thread this one. If all you radiators are hot I doubt you need a powerflush but if I was quoting and got the job, I'd, as a matter of course shove a litre of x400 in the header tank, given that's in the cupboard it's an "on the way home job".

I would supply and fit either a Vaillant echtec 831 or a viessmann vitodens 100ww and give a 5 year guarantee with both of those boliers. I would also give you the option of a bigger boiler or a cheaper alternative such as the Vaillant Ecotech Pro 28 and point out the differences. I'd also supply a programable roomstat, an give you the option of weather compensation more for comfort than big savings in a house the size of yours.

Price would be in the region of 2100 ex vat including the two rads.

 

And are you anywhere near Bexley...?

 

Hmmm, I had my system converted last year from a gravity fed to a sealed combi. Worcester CDi 30 ? The manufacturer of the combi wouldn't give a warranty on it unless the system had been powerflushed. They reckon that without the powerflush, the first thing to pack up would probably be the pump. ;-);-);-)

 

Interesting, WMc. I wonder why it would be be the pump that would fail? Are they more crappy than the old ones that have been running without probs for 20 years...?

I have to say that I would really want a powerflush (ooh-er, missus) if renewing such as large part of the system. There's bound to be some sediment sitting at the bottom of rads after all this time, and only a powerflush - as far as I understand - will shift it with any certainty. I would at least hope that quotes in the mid-£2k+ would include this as standard.

 

On the point of clean systems, it has been an established practice for some time to 'cold & hot' flush new CH systems, now, I'm not saying that every installer does this, but that will really determen the systems water condition for many years. Of course a little inhibitor is a good thing, but is a bad thing if overdone!

The system water can be checked before any chemical or power flush, to establish it's condition. Again common practice.

 

Cheers all - this thread really has been very useful. The last guy to quote is probably the one we'll go with - £1850 for Baxi 30KW Eco boiler, no new rads, chemical flush, wireless wall switch (may have misunderstood that bit!) and he's also happy to box in the flu which runs over the top of kitchen cupboards. I also got talked into a few other bits and pieces like upgrading the kitchen tap, adding a summer heater to the towel rad and he's quoted £200 to replace the existing electric shower with a mixer to benefit from the copious hot water this new setup should deliver!

Can't be done until the week just befor Christmas but happy to wait.

Thanks very much for all of your advice/help. Very much appreciated.

Sbis (couldn't log into my own account)

 

Cooool.

I have to say that my own shower is very pleasant, fed by the combi - almost 'powershowerish' when turned up to max.

You'll love it!

 

Cheers all - this thread really has been very useful..............No problem the bill is in the post.

 

Since when WB determine a power flush has to be done to enable the warranty. I take the guy who popsted that was told by someone that was the case and duly parted with a few hundred quid for the pleasure. Another reason not to fit Worcesters then but I fear it is nonsense anyway.