Boiler Advice

[Steve]

I have an Ideal Standard E type RS60 floor standing boiler which is 30 years old and still going strong. The heat input and output is 69,000 Btu/hr giving 50,000 Btu/hr at 10mBar and 82,000 Btu/hr giving 60,000 Btu/hr at

13.4 mbar.

1. Where do I check the pressure and how can I adjust it (don't know what output its set at)

2. The boiler 'kettles' with residual heat after the burner switches off (when the pump is off and the boiler is supplying hot water by gravity) - How can I stop this (noise is annoying)?

1. Is it worth switching to a condensing boiler? This is likely to cost region £2000 for a good boiler and fitting but I reckon it will take 6 years or ore to recoup the cost in gas saved.

2. I have heard a rumour that condensing boilers do not have a very long life (5-10 yrs). Is this true? What is the best material for the heat exchanger - cast iron or stainless steel (or other)?

[Andrew Gabriel]

There's probably a pressure test nipple on the burner supply, but I don't know that boiler. If you don't know how to adjust it, then you shouldn't be contemplating doing so.

It's probably scalled up inside. However, descalling such an old boiler might result in lots of leaks which are currently sealed by scale, so it could be the death of it.

Your current boiler (when properly tuned) is 65% efficient according to the SEDBUK database

if I found the right one. A new condensing boiler will be around 90% efficient, so you would get around a 25% saving in fuel costs. You didn't give your annual gas bill, but you can work out the payback based on that.

One slight issue is that condensing boilers require a lower radiator temperature for their most efficient operation. If your current radiators are undersized or only just the right size, you won't achieve quite the maximum saving. Often radiators have been oversized because builders can't be bothered to work out what they should be, so there's no problem. Even if they aren't, you can operate the radiators at a lower temperature most of the time, only turning them up to max when it gets very cold outside. Even when the radiators are running at max temperature and the boiler is no longer operating in condensing mode, it is still more efficient than a non-condensing boiler as it has a much better heat exchanger.

When replacing any boiler (since April 2002), you also have to make sure all the other parts of the heating system have modern controls, such as a timeswitch, room thermostat, and thermostatic radiator valves in other rooms. That would be the time to upgrade any existing radiator which is currently on the small size.

I would not expect more than 10 years out of any current boiler, even non-condensing ones fitted up until April. Most (all?) have microprocessor control, and you just aren't going to be able to get new parts for these 10 years after they were made. Some of the more expensive well built German ones might do better.

The best ones are stainless steel and most are aluminium alloy. Cast iron cannot be used as the condensate is slightly acidic (like vinegar) and would very rapidly corrode it.

[Marcus]

The so called efficiency of modern condensing boilers is a little misleading. Only under certain operating conditions do they have the huge increase in efficiency.

For a typical domestic home the saving will be considerably less than the

65%/90% figures would have you believe !.

[jim]

25% reduction!

total *ollacks

25% reduction on what? Take a calculation on a 20-25year basis. breakdowns / maintained contacts etc. then calculate the CO into the air!!!! you green thing's.

hope this hits home (latterly)

from ..........old guy with very grey hair - who knows better.