Reccomend me a new combi boiler?

[mattylad]

Hello all, well I had a nice surprise when I came home tonight.

Our ancient Worcester 9.24 BF electronic is not working.
The pilot light will not stay lit despite following the fault finding info in the
manufacturers instructions.

The flame looks fine (15-20mmas per the manuf instructions)

I have tested the thermocouple and that seems to be working (rising 1mv through 20mv upwards), the overheat thermostat is 0 ohm closed circuit and the flue appears to be clear (I can feel a good draught coming through it).

So now it needs a proper fella to look at it & will be looking for one in the morning.

We have discussed its age, obsolescence, existing faulty diverter valve, recent pcb soaking and how badly it works, beingon the site list of dangerous boilers and don't really think that its worth fixing if its going to cost more than a couple of hundred.

Looking at the cost of the gas valve being over £130 its certainly going to do so if thats gone.

So as well as asking various people for quotations to fit a new condensing boiler, flue, redo gas pipe, powerflush etc I'd like to get some opinions on what boiler to look for & what to avoid?

We have a 4 bedroom 3 floor terrace house, large lounge 1 rad & kitchen 1 rad, large main bedroom 1 rad, small bedroom 1 rad, 2 large attic rooms 1 rad each, small bathroom 1 rad.

All rads are using microbore and I'd expect the piping & rads to remain, just being powerflushed as its going to be far less to do before xmas.

 

[gas4you]

For top quality look at the ATAG range.

For the best in the mass produced market look no further than Vaillant.

 

[mattylad]

Cheers Dave, can you recommend anywhere that I ought to look (in Lancashire preferred)?

 

[gas4you]

Contact ATAG or Vaillant for a selection of their approved installers

 

[Agile]

You dont test a thermocouple open circuit!

It needs to be tested into a load of about 4.7 ohms and ideally compared with a new one!

They are so cheap that many RGIs just change them anyway!

Tony

 

[mattylad]

I followed this.

 

[mattylad]

Any particular Valiant combi boiler?

And if thats too expensive for me what would I be looking at for less?

 

[BigBurner]

Look at a the Broag Avantapluc 39C combi. Better than a Vaillant. It is very well priced and has integral weather compensation control. It is £917 inc VAT, that is very well priced for a 40kW boiler.

http://www.tradingdepot.co.uk/DEF/c.../Central Heating Boilers/Broag Remeha Boilers

http://www.avantaplus.com/index.php?content=39c

Look at the combi options pages 17 to 21. The outside senors, are little extra.
http://www.avantaplus.com/docs/Issue 5 -Avanta Schematics Booklet.pdf

Make sure your cold main is adequate, as for any mains pressure system.

 

[mattylad]

ooo errrr, Agile was right.
Just changing the thermocouple sorted it, so its now working again for a few more months tlle we get xmas over with then we will look at a new one.

Just been chatting with the corgi engineer about a raplacement and he was saying he has been using Broag dutch boilers without problems, they come with 5 year guarantee on all parts etc.

But can you get the parts over here?

So come the new year we may well be looking further.

How much more efficient will one of these new ones be than the old wb9.24 and what will that likely save me in gas bills per year (avg)?
Time for the old crystal ball

 

[BigBurner]

ooo errrr, Agile was right.
Just changing the thermocouple sorted it, so its now working again for a few more months tlle we get xmas over with then we will look at a new one.

Just been chatting with the corgi engineer about a raplacement and he was saying he has been using Broag dutch boilers without problems, they come with 5 year guarantee on all parts etc.

But can you get the parts over here?

Yes. They are based in Wokingham and have been in the UK a long time selling commercial boilers. The parts are pretty generic fitted to many boilers. HRPC will know the generic number (like say a Honeywell number) and just pick it off the shelf. They have next day delivery of parts to more remoter places.

How much more efficient will one of these new ones be than the old wb9.24 and what will that likely save me in gas bills per year (avg)?
Time for the old crystal ball

Difficult to say. The newer models are approx 92% efficient. Your older model with age may be around 60-70%. You should reduce gas consumption by around 20% using weather compensation and TRVs all around.

Fit a Magnaclean on the CH return to the boiler.

 

[mattylad]

Cheers Bigburner.

Re the Magnaclean, how big an issue is the iron oxides in the heating pipes?
where do they come from etc?
And how often does the MC need cleaning out itself?

 

[BigBurner]

Cheers Bigburner.

Re the Magnaclean, how big an issue is the iron oxides in the heating pipes?
where do they come from etc?
And how often does the MC need cleaning out itself?

The issue is getting it in the boilers heat exchanger(s). It comes from the corrosion process of the steel rads.

Fitted on an existing system it collects a lot within hours. After, every month and then every year at service time.

 

[mattylad]

So it extends the life of the heat exchanger...

OK, sounds like a good idea.

Cheers.