Boiler replacement.

[chunkolini]

My antique combi boiler is dying.
Heating is working but hot water is all over the shop cycling between hot and cold. Just had a valve replaced for £150. And barely any better.
They reccomend replacement.
I have heard of subsidised schemes for updating boilers. Has any body got any useful info for me.
Typical just as winter comes.
Hot water is not an issue as I never wash.
Erm I mean have a power shower.

 

[merryman]

About a month back I was getting unsolicited phone calls offering me a subsidised boiler replacement, so assume the con is back on again. You seem to need to be on benefits, or pension. I would check with your Gas supplier as they pay for it, or more accurately, the "green levy" pays for it so, indirectly, their customers.

 

[Roberto]

If your heating is fine why not think about an instantaneous leccy water heater under the kitchen sink. You can connect into the existing hot water pipework and take the boiler out the loop. £200 to £300 should cover it easy. Cheaper than a new boiler.

 

[Wozzaaah]

My antique combi boiler is dying.
Heating is working but hot water is all over the shop cycling between hot and cold. Just had a valve replaced for £150. And barely any better.
They reccomend replacement.
I have heard of subsidised schemes for updating boilers. Has any body got any useful info for me.
Typical just as winter comes.
Hot water is not an issue as I never wash.
Erm I mean have a power shower.

That can often be caused by a partially blocked heat exchanger which is a fairly cheap, easy fix.
I have a spare one, when our HW starts going hot/cold I fit the spare, clean the removed one with brick acid and put it back in the box ready for next time.

 

[chunkolini]

A good start.
I know the boiler is ancient and will need replacing in the end.
Wozzahs solution appeals.
I am not touching it myself that would be the kiss of death.
The freebie thing sounds too good to be true.
If I can get a year or two out of it that would be fine.
Would tampering with the heat exchanger screw up the rest of it?

 

[Wozzaaah]

On ours the heat exchanger is secured by two screws and seals using four O rings.
You have to remove a couple of other bits to create enough room to get it out but I've done it several times over the years and I've never had any problems.

When the water can't flow through the heat exchanger quickly enough it gets too hot so the boiler thermistor then tells the burner to modulate down then once it's cooled down the burner roars back into life until it gets too hot again.... and so on.
If you get an engineer out and they change the HE, insist on keeping the old one.

 

[armalites]

When the heat exchangers scale up the temperature rises very quickly on the water as the flow is restricted. It then shuts down and once the temperature drops away then fires up. That's where the cycling comes from.

As @Wozzaaah says cleaning the heat exchanger may fix it, the problem is if it has never been out then you may have some fun with the scaled up connections

 

[chunkolini]

That all makes a degree of sense, hence the cycling.
The boss man at the plumbers is after selling me a new system.
The underling hinted that he might have a SH newish heat exchanger, maybe we can 'work something out' I will give him a call

 

[Kayos]

It’s all ended, it’s mostly a ploy to get in the door these days

Not to be political but David Cameron cut it several times to the point of most people not being eligible for anything

 

[keithski122]

My neighbour had a subsidised one fitted years ago, cost more than getting one fitted privately.I had mine replaced last year, boiler cost £1200, don't know about fitting as that was part of house extension costs.Plumber recommended mr cenral heating for supplying as he was fitting only (no vat) but in the end he got me one from local bradfords.

 

[maz0]

On ours the heat exchanger is secured by two screws and seals using four O rings.
You have to remove a couple of other bits to create enough room to get it out but I've done it several times over the years and I've never had any problems.

When the water can't flow through the heat exchanger quickly enough it gets too hot so the boiler thermistor then tells the burner to modulate down then once it's cooled down the burner roars back into life until it gets too hot again.... and so on.
If you get an engineer out and they change the HE, insist on keeping the old one.

This is spot on. Had an ideal logic for 5 years that got the HE changed twice a year for the duration of the 5 year warranty. When it was up to me eventualy I took the HE off and used Rhino drain unblocker on it (95% sulphuric acid). Worked a treat!

 

[Kayos]

This is spot on. Had an ideal logic for 5 years that got the HE changed twice a year for the duration of the 5 year warranty. When it was up to me eventualy I took the HE off and used Rhino drain unblocker on it (95% sulphuric acid). Worked a treat!

They are known to fail, I wouldn’t be using sulphuric acid on an aluminium heat exchanger though

 

[Muppet]

I fitted an ideal piece of junk, or boiler as British Gas call them four years ago,
and have to clean the heat exchanger every year from new,
If I don't it cycles on off , over heat comes on,
Caustic soda first , then ultrasonic bath, most hot water heat exchangers are SS,

 

[Wozzaaah]

They are known to fail, I wouldn’t be using sulphuric acid on an aluminium heat exchanger though

I think it’s stainless and copper, it’s certainly not alu.
Brick acid seems to work really well, not sure what % sulphuric it is without looking.

 

[Wozzaaah]

I fitted an ideal piece of junk, or boiler as British Gas call them four years ago,
and have to clean the heat exchanger every year from new,
If I don't it cycles on off , over heat comes on,
Caustic soda first , then ultrasonic bath, most hot water heat exchangers are SS,

Ours is an Ideal Mini, if I didn’t know it inside and out and was scared to get stuck in, it would have cost us a fortune in repairs over the years.
I also have a spare PCB for it too so when (not if) the solder joints go dry I swap that and repair the old one ready for the next time.

 

[Kayos]

I think it’s stainless and copper, it’s certainly not alu.
Brick acid seems to work really well, not sure what % sulphuric it is without looking.

Main heat ex is alu, hot water is as you say.

 

[Wozzaaah]

Yes sorry, it’s the DHW one.