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Hi,

Can I pick your brains?

My boiler is often reluctant to start, sometimes it does, sometimes it seems that it will if the demand is from the central heating but not for hot water and sometimes the other way round, so it's probably just luck as to when it does decide to work[?]. When there's demand, and it doesn't fire, there is a humming/quiet ticking sound that fades after a few seconds, and when the demand ends there a whirring that sounds like a valve being closed[?]. The Water Heating or Demand lights don't come on, let alone Ignition or Flame - that's all the display I have. The pump will start to get hot if I try for too long or too often. It usually starts eventually but sometimes refuses but then works perfectly later in the day. Once I tried it at the kitchen tap to make sure it was working before going to shower and it worked downstairs but not five minutes later upstairs. The pump spins freely enough with a screwdriver but if it's not firing correctly there is absolutely no sign of movement of the spindle when demand is made. Sometimes, once it's running, the shower - an old thermostatic Aqualisa - will alternate between unbearably hot and almost cold [I thought it was designed to keep a steady temp regardless of the hot supply...?] Reading other questions here these problems seem to point to a faulty run capacitor. It's nearly 30 years old but it looks OK - no bulges, leaks or splits - but considering how often you had to change fluorescent tube starters I guess it's done pretty well.

Does anyone think this is likely to be the problem and it's worth trying to fit a new one? Do they fade away or just go from working to not working at all? The boiler is so far past its prime it's not worth the cost of a new pump or anything else on that scale, but a few quid for a new capacitor would be great if it kept it going a little longer.

BTW, I can't see me ever opting for a heat pump on space, cost and convenience grounds, and with the future of gas uncertain does anyone have any opinions on electric combi boilers to be used without hot water storage? I don't use much gas so I can imagine the savings on standing charges for gas, servicing and maintenance might balance the higher energy costs, but do they work well enough? One concern is just getting a heavy duty power supply to the boiler - I've no idea what that would involve.

Many thanks.
 
To me it sounds like a relatively easy fix.

Get someone qualified to have a look at it for you.
Could be a easy as changing a sensor.

What brand of boiler is it?
 
I don't do a lot of electric boiler installs but I would expect they are still a way off the mark of gas combi's.

Think an electric shower which is typically 10.5kw max and how bad the flows are on them then try and run your whole house on it. Most houses in the UK are 18kw max supply now add your ring main at 7.5kw and the other circuits you can see you can't really get more out of it without special alterations to your incoming electrics (pure speculation based on what I can find online, I know my merchants had issues with 14kw combi's because no house could take it)

A gas combi would normally have at least 24kw minimum but gas is 1/3 of the cost of electric per kw.

If your boiler is 30 years old I would expect the plumber to tell you its time for a new one after a small amount of diagnostics unless its something obvious and cheap.

In my opinion gas isn't going anywhere in the next 10-15 years and by then your boiler will be at the end of its life and can re-evaluate again
 
To me it sounds like a relatively easy fix.

Get someone qualified to have a look at it for you.
Could be a easy as changing a sensor.

What brand of boiler is it?
I hope you're right about it being an easy fix...

It's a Potterton Lynx 2. I had 3 different BG engineers look at it when I had cover for it, they changed the main board and fiddled about a bit but none of them looked at the run capacitor or made it work any better.
 
I don't do a lot of electric boiler installs but I would expect they are still a way off the mark of gas combi's.

Think an electric shower which is typically 10.5kw max and how bad the flows are on them then try and run your whole house on it. Most houses in the UK are 18kw max supply now add your ring main at 7.5kw and the other circuits you can see you can't really get more out of it without special alterations to your incoming electrics (pure speculation based on what I can find online, I know my merchants had issues with 14kw combi's because no house could take it)

A gas combi would normally have at least 24kw minimum but gas is 1/3 of the cost of electric per kw.

If your boiler is 30 years old I would expect the plumber to tell you its time for a new one after a small amount of diagnostics unless its something obvious and cheap.

In my opinion gas isn't going anywhere in the next 10-15 years and by then your boiler will be at the end of its life and can re-evaluate again
Thanks. I was afraid that would be the answer! It says something that with all the supposed advances you only expect a new boiler to last 10 years when my basic old one has lasted 30 - just.
 
I think its more economics really. 10 year warranties on some of the new boilers. The parts and labour costs are the expensive bit so why not just put another new one in for 10 year warranty again. It's become a bit like owning a car.
 
I think its more economics really. 10 year warranties on some of the new boilers. The parts and labour costs are the expensive bit so why not just put another new one in for 10 year warranty again. It's become a bit like owning a car.
Last year I spent about £40 on gas for virtually all my heating and hot water. A warranty will involve an annual service at around £100 and then there's the gas standing charge at about £50, so that's in the region of £200 a year to get £40's worth of heat, which makes little sense even before you think about the cost of the boiler itself. That's why an electric boiler would suit me so well - if they worked better
 
I hope you're right about it being an easy fix...

It's a Potterton Lynx 2. I had 3 different BG engineers look at it when I had cover for it, they changed the main board and fiddled about a bit but none of them looked at the run capacitor or made it work any bette
It’s probably totally obsolete just looked up a posting on another site from 2014 and the boiler was 23 years old then. You’ve had your money’s worth out of it time to change it. It’s non condensing and nowhere near as efficient as a new boiler
 
3x the cost of gas so if you use £50 a month of gas this will roughly add upto £150 in the same etc
 
If you're only spending £40 pa and as above you're not paying a standing charge who's providing your gas and what size of space/property do you heat and with what?
 
It’s probably totally obsolete just looked up a posting on another site from 2014 and the boiler was 23 years old then. You’ve had your money’s worth out of it time to change it. It’s non condensing and nowhere near as efficient as a new boiler
Yes, it's totally knackered but I have no money and if a new boiler is 10% more efficient it will save me £4 pa but cost £2.5k, so I'll get my money back by 2650!
 
Yes, but with such low usage the standing charge and service costs make gas more expensive.

Not really as you would still have a standing charge even with no gas usage

There are grants about for new boilers might be worth asking your gas supplier
 
10C is no temperature at all and you risk getting hypothermia, in what part of the country do you live?

As above you may qualify for a new boiler grant.
 

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