Boiler swap. INTEC 40GS to Worcester Greenstar 32CDi Compact Combi

[gmartine]

Two things, as you've discovered the external size (casing) for the compact CDi range is the same whatever the power rating of the boiler.

The flowrate you listed from WB is l/m @ 40 degrees whereas the max flowrate from your Alpha you highlight is l/m @ 30 & 35 degrees C. Easy mistake to make so to compare like for like, find or phone WB for the 36CDi data sheet and get the numbers for l/m @ 30 & 35 degrees C for a fair comparison.

 

[Chuck]

I think they are quoting for it because of the space. Please see my response to Scott above. We are trying to free up the space to install an additional set of stairs into the loft and have some unused space in the bathroom.

It would be a lot cheaper to put a cupboard in the bathroom to use the space than to move the boiler. One possibility I'd find attractive would be to create a drying cupboard with a dehumidifier, which could have its drain plumbed in.

Be careful about how you use the roof space in a new house. The joists are often 'engineered', i.e. won't take much additional load. Also, there'll be a lot of insulation that you can't compress down without problems.

 

[TonyS]

Two things, as you've discovered the external size (casing) for the compact CDi range is the same whatever the power rating of the boiler.

The flowrate you listed from WB is l/m @ 40 degrees whereas the max flowrate from your Alpha you highlight is l/m @ 30 & 35 degrees C. Easy mistake to make so to compare like for like, find or phone WB for the 36CDi data sheet and get the numbers for l/m @ 30 & 35 degrees C for a fair comparison.

Excellent point! I did have to 'hunt' for the 35 degree value for the Worcester, but found it here

36CDi Compact - 14.7 @ 35°c ∆T
InTec 40 GS - 15.6 @ 35°c ∆T

This isn't such a big difference. I hope I can trust these numbers!

 

[gmartine]

Do a HW flow test and see if it's true.

 

[TonyS]

Do a HW flow test and see if it's true.

Bath tap
6 seconds - 1 litre = 10 litres per minute

and, while the bath tap keeps running:

Bath sink
6 seconds - 0.5 litres = 5 Litres per minute

I don't know what the maximum could be, but it definitely does 15 Litres per minute.

 

[Ben-gee]

Was the basin tap running when you measured the bath?

Otherwise you could have had 10 at bath, but this dropped (to say 5) when you measured the basin at 5. - in which case you only have 10, not 15.

Just checking your method

 

[TonyS]

Was the basin tap running when you measured the bath?

Thank you for checking! Yes, I opened both initially, allowed the water to run for a few seconds to get hot, then proceeded to place the kettle under each facet

What may have hindered the measurement is that I think that our sink tap has a flow restrictor/aerator and I couldn't get the maximum flow tested (with the sink being limited).

 

[king of pipes]

A viessmann100 would be my choice for you bin the worcester idea this boiler would future proof your property and can get a 10 year warranty if fitteded by a accredited installer H2 ready built in wifi really well thought out , and dont forget you can only get out what you can put in , as winter approaches water temperatures in the ground will drop and as a consequence your litres per minute will reduce for hot water . Kop

 

[gmartine]

You fitted many KoP? It's a touch deeper than the offered WB but I agree it's worth it. Didn't realise the HW flow rate was that good and I did the bliming course.

 

[TonyS]

A viessmann100 would be my choice for you bin the worcester

Thank you for the suggestion! Apart from WiFi I don't yet see why it's a better choice.

It's as large as our existing InTec G40 and as powerful
There will be a 10-year warranty on the Worcester too, as I was told

As much as I like the appeal of the technology coming from the country highly dependant on gas (Germany), and therefore knowing a good boiler, I can't see how it's better at this stage