Heat exchanger

flimflams

Re my previous post "water cylinder"

I was wrong and the part is called the heat exchanger (combined boiler). The gas engineer said it costs around £1000 to replace and that I should unfortunately get a new boiler. 
Researching online seems to suggest that it would be cheaper than getting a new boiler.

Is the engineer having me on? 

flimflams

Hi,

I haven't had hot water and heating for a while. The gas engineer showed that the cylinder has been running dry and has a burnt mark. Like when you are boiling water in a pan and the water boils off and the pan is still on the heat.
The engineer said that it's not worth replacing the cylinder, costs at least £1000. He said that we should replace the boiler. He gave us an expensive quote, but I have since found that a new boiler is a bit cheaper going through Worcester boilers.

I am wondering If I do really need to spend on a new boiler or can I just replace the water cylinder?

luci

You should get quotes from an independent heating installer for both a new boiler and a new HW tank. That should help you decide. This might give you an idea of the cost, although I've never used the site:
https://www.boxt.co.uk/

If it were me, I would get a new combi boiler, as it doesn't need a HW tank. We have just replaced a condensing boiler with a combi and it's the best thing we could have done. You only heat the water you use, rather than a whole tank. We've also noticed that the radiators heat up quicker.

flimflams

Maybe I am not using the correct name for the part, idk.
The boiler is a combination boiler and I am referring to the metal cylinder.

luci

I thought you meant a HW tank / cylinder. I don't know anything about metal cylinders, so I would go with my first paragraph.

flimflams

luci said:

You should get quotes from an independent heating installer for both a new boiler and a new HW tank. That should help you decide. This might give you an idea of the cost, although I've never used the site:

If it were me, I would get a new combi boiler, as it doesn't need a HW tank. We have just replaced a condensing boiler with a combi and it's the best thing we could have done. You only heat the water you use, rather than a whole tank. We've also noticed that the radiators heat up quicker.

It's a small metal cylinder in a combi boiler. Whatever that's called

luci

flimflams said:

luci said:

You should get quotes from an independent heating installer for both a new boiler and a new HW tank. That should help you decide. This might give you an idea of the cost, although I've never used the site:

If it were me, I would get a new combi boiler, as it doesn't need a HW tank. We have just replaced a condensing boiler with a combi and it's the best thing we could have done. You only heat the water you use, rather than a whole tank. We've also noticed that the radiators heat up quicker.

It's a small metal cylinder in a combi boiler. Whatever that's called

I may be wrong, but I think that's called an expansion tank.

Rodders53

luci said:

You should get quotes from an independent heating installer for both a new boiler and a new HW tank. That should help you decide. 
Agreed.  Best bit of advice you've given.
Also consider getting quotes for an Air sourced heat pump ASHP installation as well? (Before the government subsidies disappear.)

If it were me, I would get a new combi boiler, as it doesn't need a HW tank. We have just replaced a condensing boiler with a combi and it's the best thing we could have done. You only heat the water you use, rather than a whole tank.
NOOOO!!!!   An unvented HW tank gives a far superior shower/showers in larger households, and will be needed for when an ASHP is required at a future date.

We've also noticed that the radiators heat up quicker.
That's because a combi will be stupidly over-rated heat output (needed for the HW) and probably won't modulate down enough to keep the home heating ticking over and therefore short cycle.

I have to wonder exactly what has happened to this HW cylinder... HOW has it run dry and how has such damage happened (even with an electric immersion element in use they have overheat cut-outs that don't reset)?

luci

Rodders53 said:

luci said:

You should get quotes from an independent heating installer for both a new boiler and a new HW tank. That should help you decide. 
Agreed.  Best bit of advice you've given.
Also consider getting quotes for an Air sourced heat pump ASHP installation as well? (Before the government subsidies disappear.)

If it were me, I would get a new combi boiler, as it doesn't need a HW tank. We have just replaced a condensing boiler with a combi and it's the best thing we could have done. You only heat the water you use, rather than a whole tank.
NOOOO!!!!   An unvented HW tank gives a far superior shower/showers in larger households, and will be needed for when an ASHP is required at a future date.

We've also noticed that the radiators heat up quicker.
That's because a combi will be stupidly over-rated heat output (needed for the HW) and probably won't modulate down enough to keep the home heating ticking over and therefore short cycle.

I have to wonder exactly what has happened to this HW cylinder... HOW has it run dry and how has such damage happened (even with an electric immersion element in use they have overheat cut-outs that don't reset)?

I have to disagree with you regarding the shower being far superior. Not in my experience. We have a vastly greater flow with the combi than we ever did with the gravity fed system. We are not a larger household, so don't have several people using water at the same time.

Over rated or not, our gas bills are lower with the combi.

luci

flimflams said:

Re my previous post "water cylinder"

I was wrong and the part is called the heat exchanger (combined boiler). The gas engineer said it costs around £1000 to replace and that I should unfortunately get a new boiler. 
Researching online seems to suggest that it would be cheaper than getting a new boiler.

Is the engineer having me on? 

You should get quotes from at least 3 Gas Safe engineers

Nearlyold

An unvented mains pressure HW cylinder system  (not to be confused with a gravity fed tank system) will be way better than any combi in terms of pressure.