Changing a very low output system boiler?

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Hi, I have a trusty baxi solo 3 30 PF system boiler nearing 25 years old, still going, but probably not for long :)

Its rated output is 5.86 - 8.79 kw, which is *more* than enough for my *small* well insulated house (output is always set below medium on boiler). It heats my open vented Y plan system (4 rads/water tank/power shower pulling water from my hot water tank)

My GAS bills are VERY low in winter with heating on most of the day :)

The lowest output entry level open vented system boiler I could find is this one, but still rated at 18KW output...

https://www.mrcentralheating.co.uk/vokera-easi-heat-plus-18v-open-vent-boiler-with-horizontal-flue

I downloaded the installation manual and although above my head seemed to indicate that a competant installer can tweak the output too demand

So was wondering if an installer can limit the output to say 8KW, so it never goes above it?

PS Was also interested in any "alternative" ideas for heating instead of gas, for example was thinking along the lines of not having a boiler, just use the heating element in the hot water tank to heat my house on demand (opening the 3 way valve as needed with my thermostat switching the hot water element on/off). The additional electricity cost over gas would easily be covered by the £1000 needed to change the boiler!
 
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The Worcester Ri is available with a 9Kw max output...this model's well proven having been around since 2005 ish.
 
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My Baxi Solo 3 60PF was installed in 2000 and still works perfectly. It has a robust heat exchanger and is nice and simple because it's not a combi or condensing (it does have one of the best efficiencies of non condensing boilers). It's had a few new parts over the years notably a fan and two PCB's but in most cases it worked even with the fault (the fan was a bit 'screechy' and one PCB didn't switch off the pump) but was speedily repaired every time. The longest time it has been out of service for in 19 years was for 4 hours due to a pressure switch failure. Parts are still readily available, so I plan to hang on to it for as long as I can. Hopefully by the time I need to replace it the new boilers will have a longer lifespan than they do now.....;)
 
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My Baxi Solo 3 60PF was installed in 2000 and still works perfectly. It has a robust heat exchanger and is nice and simple because it's not a combi or condensing (it does have one of the best efficiencies of non condensing boilers). It's had a few new parts over the years notably a fan and two PCB's but in most cases it worked even with the fault (the fan was a bit 'screechy' and one PCB didn't switch off the pump) but was speedily repaired every time. The longest time it has been out of service for in 19 years was for 4 hours due to a pressure switch failure. Parts are still readily available, so I plan to hang on to it for as long as I can. Hopefully by the time I need to replace it the new boilers will have a longer lifespan than they do now.....;)

Interesting ..... Just out of interest were in the country are you, who do you use please?

I've had various engineers around to look into my itermittent problems, but I get the feeling they are either just wanting me to install a new boiler, or worried that they dont really have the experience of fault finding beyond "change the pcb" :)

I like the system because its simple so I can fix myself, I drain/flush and put in inhibitor every few years and have changed my 3 port valve and pump

But above all I like the fact that in this old system I have a backup immersion heater for hot water/shower if my boiler dies, so no emergency (costly) visit

It has stopped making excessive clicking noises on firing up, but has now started to cycle so that its switches on for about a minute, switches off for about two mins, then switches back on for 1 min etc.... My house still warms up nicely because its well insulated, but am worried that the continous cylcing will break something else

I purchased a pcb a while back, but dont want to touch the boiler whilst its still (semi) working !!
 
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Sensible choice.

Hi, I was under the impression that the new system boilers are like the baxi (a lot simplier than the combis), thats why I want to stay away from combi's, or are they just as complicated these days as the combis?
 
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The clicking is probably because it's slow to ignite. It's a known Solo 3 issue caused by the fan pulling the gas away from the pilot light making it difficult to light. Mine usually does it a few times when it lights up for the first time from cold.

it switches on for about a minute, switches off for about two mins, then switches back on for 1 min etc.... My house still warms up nicely because its well insulated, but am worried that the continous cylcing will break something else

That's how it works. The Solo 3 boiler thermostat is simply a on/off switch, so the burner will fire until the water in the boiler reaches the set temperature on the thermostat dial, then it will go off, when the water has cooled sufficiently it will re-ignite. If it kept going, the water would boil. Normally it will continually for a while when heating up the system from cold, and then as the system warms up the 'off' periods get longer and the 'on' periods shorter.

I'm in North Nottingham. The previous guy who installed it in 2000 retired and now his son looks after it for us. His Gas Safe licence number is 543079, so if you search the Gas Safe register you can see all of his contact details. Because I know it that well now, if it does have a problem I can usually give him an idea of the problem when I call him.
 
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I was under the impression that the new system boilers are like the baxi (a lot simplier than the combis)

System boilers are the boiler, circulating pump and other components packed into a single case, easier to install but often harder to service due to the cramped space inside the case.

Heat only boilers have the pump and other components mounted independently from the boiler and its case are much easier to service.

Combi boilers were originally intended for flats and small houses where there was no space available for a hot water tank. They became popular with installers as the installation is much simpler when there is no hot water tank to install.

they are either just wanting me to install a new boiler, or worried that they dont really have the experience of fault finding beyond "change the pcb"

There are too many installers who have little ability at fault finding.
 
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The clicking is probably because it's slow to ignite. It's a known Solo 3 issue caused by the fan pulling the gas away from the pilot light making it difficult to light. Mine usually does it a few times when it lights up for the first time from cold.



That's how it works. The Solo 3 boiler thermostat is simply a on/off switch, so the burner will fire until the water in the boiler reaches the set temperature on the thermostat dial, then it will go off, when the water has cooled sufficiently it will re-ignite. If it kept going, the water would boil. Normally it will continually for a while when heating up the system from cold, and then as the system warms up the 'off' periods get longer and the 'on' periods shorter.

I'm in North Nottingham. The previous guy who installed it in 2000 retired and now his son looks after it for us. His Gas Safe licence number is 543079, so if you search the Gas Safe register you can see all of his contact details. Because I know it that well now, if it does have a problem I can usually give him an idea of the problem when I call him.

Oh Ok thanks thats reassuring
 
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System boilers are the boiler, circulating pump and other components packed into a single case, easier to install but often harder to service due to the cramped space inside the case.

Heat only boilers have the pump and other components mounted independently from the boiler and its case are much easier to service.

Combi boilers were originally intended for flats and small houses where there was no space available for a hot water tank. They became popular with installers as the installation is much simpler when there is no hot water tank to install.



There are too many installers who have little ability at fault finding.

Thats usefull to know, *if* i ever change my baxi then..... I'll look for a heat only boiler.... I can easily change the grundros pump myself in future if it ever died, not so with the pump in the system boiler :)

PS Although with the way things are going the future replacement will probably be something like this .... https://www.screwfix.com/p/heatrae-sadia-amptec-c400-electric-heat-only-flow-boiler/223fr (my fuseboard is conveniently right next to my boiler I reckon i could fit that in myself and then get an electrician to finish it off)
 
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Electric is very expensive compared to gas, but handy to have as a standby for when the gas boiler is faulty.
 
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Electric is very expensive compared to gas, but handy to have as a standby for when the gas boiler is faulty.

I was thinking might do the rough calculation.... I only use just over 5500 KWh of gas per year, wonder how much the extra cost of an electric boiler will compare to gas over say 5 years to the cost saving of a cheaper electric boiler (compared to a heat only gas boiler) and the bigger saving from fixing/plumbing it all in myself and the 100% efficency compared to the gas boiler with no servicing (minus cost of the electrician to do the final wiring)
 
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