40kw Combi or Hot Water Cylinder ???

[Bobcat1974]

My Gledhill 125 litre vented indirect tank/cylinder in my loft is leaking and needs replaced. It's been heated by a glow-worm economy plus 40F (max heat output 11kw) boiler in my garage - both about 15 years old.

I'm getting various recommendations from heating engineers, one has said replace with an unvented cylinder (Telford Tempest) and another has recommended a combi system (Baxi Duo-Tec He 40kw)

I've got a 3 bedroomed detached house with 2 mixer showers, a bath and 11 radiators, just me, my wife and baby living here.

Would the baxi 40kw be good enough to ensure good shower / bath pressures/flow and cw heat etc.?

Total price for combi job = £1600
Total price for cylinder job = £1250

Any thoughts ??

 

[linkyplumb]

Has any of the guys checked incoming water pressure/flow rate?

Graham

 

[Bobcat1974]

No they've not physically checked the mains water pressure. It is quite powerful though, approx 3 to 5bar... I think

 

[electronicsuk]

No they've not physically checked the mains water pressure. It is quite powerful though, approx 3 to 5bar... I think

Then I certainly wouldn't bother calling either of them back. Without checking dynamic pressure and flow rates, those installers have absolutely no way of knowing whether or not you'll be able to achieve the full potential out of either an unvented cylinder or a combi, therefore they shouldn't be recommending those products to you.

 

[Bobcat1974]

What is the ideal mains pressure then?

To be fair the guy recommending the baxi duo-tec hasnt been round yet, he's awaiting a call from me to ask him round to check 1st.

 

[Bobcat1974]

http://www.baxi.co.uk/docs/Baxi_DuoTec_brochure.pdf

Is the 40kw version of this at the high end of general combi output. I can get one one for £840.

I assume 16 litres @35degC a min is pretty good DHW output.

Any thoughts or experiences ??