Old boiler problems!

[alpha45]

My 11-year-old Potterton Kingfisher will need relacing before long.

A contractor has assured me that a British/Scottish Gas 537 High Efficiency
Combi Boiler (apparently also known as a Worcester Bosch 542) will be adequate to supply a detached 5 bedroomed house with a tenanted granny flat. In all there are 2 bathrooms on the first floor with 2 showers and a bath and on the ground floor there are 2 kitchens and one bathroom with a bath and shower.

I would be really grateful for your reactions, ideas, suggestions and advice.

Alpha45

 

[bengasman]

1. It is unlikely that your existing potty will need replacing any time soon, more likely than not you have fallen victim to a fast talking sales shark.
2. A large combi (~40 kW) will happily supply 2 normal showers simultaneously.

 

[linkyplumb]

Plenty of life in the old potty yet.IMHO

Graham

 

[Tibbot]

What is the problem with your Potterton Kingfisher?

 

[Boilerman2]

Do not fit a combi in a house of this size especilally with an annexe as well keep your stored hot water system - Combi's are not always the best solution especially in your case!! get advice from some more engineers!!

 

[Whitespirit66]

Keep your Potterton for a few more years, and don't change it just to save a few quid on gas.

In the future, if it gets terminal, replace with another heat only boiler. You may consider a minor alteration from your vented system to sealed when you change boilers. But keep the stored water.

 

[ChrisR]

A British Gas 542 is a Worcester Bosch 42cdi.
It's entire output would fill a bath slower than a straightforward old fashioned bath tap on an old system gravity fed from the floor above. And you've got 3 bathrooms.

42kW is 15 litres a minute with a 40º temperature rise. In the winter the incoming water is at about 5º, and we all fill a bath at about 45º
The old tap would give 20 litres/minute, at whatever temperature you store it at, perhaps 55º so you can add cold to make it even quicker.

If you have showers running on two different floors running from a combi like that, the upper one will suffer a lot and be very sensitive to another hot tap being turned on somewhere.

British Gas really don't do themselves any favours when they suggest something like that.