Boost to old Worcester Boiler

[GeorgeNewman]

My trusty Worcester Heatslave 2+ boiler, now running for 34 years without any serious faults, does have one disadvantage.

Its output to water is only 11kw which makes running a bath slow, especially in winter. I had a word with my electrician last year and he suggested heating the cold water input with an inline electric unit. (I hadn't heard of these previously.)

Suffice it to say addition of a 9.5kw Redring Powerstream fitted just prior to the boiler has made all the difference -I now get 6 litres/min of continuous piping hot water.

A few tech details: Mains cable 10 sq.mm, three core straight to consumer unit, on a dedicated 45A rcd. 60A double pole switch to isolate heater. 6Bar pressure relief valve fitted after the non-return valve, to drain. (Details courtesy of my electrician, Peter.)

Most domestic combi boilers are much more powerful than mine these days, but this is a good workaround for anyone who needs a bit of a boost to their hot water flow. And it provides a hot water backup if the boiler is temporarily out of service - reverse heat flow through the boiler heat exchanger is minimal as long as the circulating pump if switched off.

It's been working perfectly now for almost a year. Brilliant! And one can turn it down to half power in the summer, when mains cold water warms up.

Best, George.

 

[Nige F]

Have you got a 1/4" steel box bolted to the wall over the water heater in case it blows up

 

[bernardgreen]

So much better to have a heat only boiler and an hot water tank. Fills the bath very quickly.

 

[picasso]

6 ltrs a minute life in the fast lane eh

 

[GeorgeNewman]

Thanks for comments!

No space for a hot water tank, thus the original installation of a combi.

6 litres/min of water with a 50 degree temp rise - equates to about 10 litres/min of bath hot water, i.e. 20kw heat input. Quite respectable for a continuous hot water supply, even by today's standards.

'Have you got a 1/4" steel box bolted to the wall over the water heater in case it blows up'

Safety, first, always. The system is fully protected against runaway heating and over-pressurisation. But thanks for your concern, Nige.

 

[Tibbot]

Oh dear, Dr Drivel back again. What happened to the Vokera SE you had fitted in your last post/alias?

 

[Groovejet]

Dont understand??

Are you saying that you've linked the powerstream upto mains pressure and then connected into your existing hot water pipe???

The heatslave is a floor standing combi, has it been tested to see if it is running at 11kw or is capable of increasing the kw output.

Has the thermostat been tested for accuracy/working correctly?

 

[GeorgeNewman]

Groovejet,

'Are you saying that you've linked the powerstream upto mains pressure and then connected into your existing hot water pipe???'

The Powerstream is on the cold water input side of the boiler, not the hot water o/p side.

'The heatslave is a floor standing combi, has it been tested to see if it is running at 11kw or is capable of increasing the kw output.'

It is running at 11kw o/p to water - tested ok. The burner pressure cannot be increased beyond 11kw o/p.

'Has the thermostat been tested for accuracy/working correctly?'

Yes - it is working correctly and is accurate.

The addition of the Powerstream simply heats the incoming mains cold water and increases hot water up to 20kw heat input, making baths quicker to run.

The central heating side of things has always been more than adequate for my house. I use about 2kw average during the day in winter.