Replace old faulty boiler/heating with combi?

spaceraiders

I've been in my new house for about 6 months:

- It has only 1 bedroom, 1 bathroom and 3 radiators so it doesn't need a lot of hot water.
- I have a traditional heating and hot water system (e.g. boiler + hot/cold tanks).
- The boiler seems to be about 5 or 10 years old (the previous owners gave me no information about it).
- The water tanks, pump, piping etc. look neglected as they're covered in dust and don't look like they've been serviced for a long time.

Recently, all the radiators started leaking clear water (water leaves a slight orange stain after evaporating) for rust patches at the bottom. The hot water and heating are only mildly warmer when the system is turned on. I can feel the hot water coming from the boiler but not out from the hot water tank. I suspect the pump might be broken.

A friend suggested I look at replacing the system with a combi boiler instead of repairs. He thinks I'll probably have to spend £400/500 on new radiators + power flush + repairs.

I was given an estimate of £1600 for parts and labour to install a new combi boiler + 3 new raditors + new piping + removal of old boiler. The advantages of this would be:

- I'd gain a decent sized cupboard for storage (1mx1mx2.5m) from removing the unneeded water tanks.
- Usual combi benefits: instant hot water, effecient heating.
- New piping means I can place raditors in more appropriate places and get bigger ones (current ones are inadequete).
- Can replace my electric shower (my current hot water pressure is poor), which would be more effecient.

I'm probably looking to sell the house in 4 years or so. Comparing the cost of making repairs, I thought that the combi option is more attractive for buyers (seeing as sellers will have show energy ratings of house as well) and the extra space is an advantage.

Any advice? Would I just be wasting money? Would I make the money back when selling?

Thanks.

david29dpo

£1600 sounds a good price. I would rip the lot out and replace. Its not all about money, your quality of living is also important. It will help a sale.

macman

Change the rads, flush, fix pump if broken. You'll have to do all this with a new boiler or without. A 5 year old boiler should not be on it's last legs yet. That should be a lot less than a new system.
After that you can still change the boiler if you want.

brig001

Are combi boilers more efficient?
Condensing boilers are, but that isn't the same thing.

Combi - instant hot water.
Condensing - uses heat from the flue gases to assist.

thechippy

brig001 wrote: »

Are combi boilers more efficient?
Condensing boilers are, but that isn't the same thing.

Combi - instant hot water.
Condensing - uses heat from the flue gases to assist.

All boilers are now condensing, whether system or combi.

Ebe_Scrooge

Personal preference really. My wife still cannot understand the difference between Combi and Condensing :-)

Personally I like the Combi option - efficient in that you're not heating water that you don't need, you never have the problem of running short of hot water, and more space in your loft as there's no need for storage tanks. Having said that, the flow rate is generally slower than that of a traditional system. Combi's these days are miles better than they used to be, when they could only deliver a slow trickle of hot water. But you'll probably still notice it's slower than if you've got a tank full of stored hot water. Personally I don't find it a problem as I almost never use the bath ( prefer to shower instead, before you think I'm stinky ! ). And the flow rate is fast enough to give a really good shower, fill the sink for washing dishes, etc.

spaceraiders

macman wrote: »

Change the rads, flush, fix pump if broken. You'll have to do all this with a new boiler or without. A 5 year old boiler should not be on it's last legs yet. That should be a lot less than a new system.
After that you can still change the boiler if you want.

The new system might need new piping though as the pressure from the combi might cause leaks, plus the old piping is very thin so doesn't carry water as fast. I really need to have radiators moved and resized as well (the bedroom radiator is about half as big as it should be and it's in a place that wastes most of wall that a cupboard or something could go against) so piping work needs to be done there too.

I realise I'm probably paying a few £100 for the benefits of a combi but, weighing up the options, it doesn't seem like I'll be paying that much more for it seeing as what I need to do with the current system. I'm just checking my rational as £1600 is a lot of money, but seems worth it spread over a few years.

spaceraiders

Ebe_Scrooge wrote: »

Personal preference really. My wife still cannot understand the difference between Combi and Condensing :-)

Personally I like the Combi option - efficient in that you're not heating water that you don't need, you never have the problem of running short of hot water, and more space in your loft as there's no need for storage tanks. Having said that, the flow rate is generally slower than that of a traditional system. Combi's these days are miles better than they used to be, when they could only deliver a slow trickle of hot water. But you'll probably still notice it's slower than if you've got a tank full of stored hot water. Personally I don't find it a problem as I almost never use the bath ( prefer to shower instead, before you think I'm stinky ! ). And the flow rate is fast enough to give a really good shower, fill the sink for washing dishes, etc.

Cheers for the reply. How do you find the shower pressure compares to an electric shower? My electric shower isn't great. Gas is cheaper than electric so I like the idea of the boiler powering the shower. It's one less thing to break too.

Did you ever have any problems with low water pressure? For example, flow rate is meant to go down in the winter as it takes longer to heat up the colder water.

macman

Standard piping is 15mm, are you saying your existing one is a microbore system?
Is the combi pressure on the CH side going to be any different to a conventional pumped system?
Actually as you have such a good price, I would probably go with your plan to renew completely, but it may not be technically necessary.
Are you sure that price includes the room thermostat/programmer, TRV's etc-and VAT?

spaceraiders

macman wrote: »

Standard piping is 15mm, are you saying your existing one is a microbore system?

The pipes to the radiators are about 10mm in diameter.

Is the combi pressure on the CH side going to be any different to a conventional pumped system?

I don't know but will find out.

Actually as you have such a good price, I would probably go with your plan to renew completely, but it may not be technically necessary.
Are you sure that price includes the room thermostat/programmer, TRV's etc-and VAT?

One of my friends does a lot of flat development/improvement work so is able to get good prices on parts. The quote I have would involve us getting the parts and paying for the labour so the price appears good as far as I can see. I'm fairly sure it includes everything, such as thermostat.

Thanks for the questions/advice. I don't really know anything about boilers so your questions are helping me know the right things to find out.

I'm mainly worried that this older system is going to be a nightmare to maintain in the future. The combi seems like an easy (but expensive) fix and I get other advantages with it too. If I got British Gas to inspect the current boiler for their £100 or so price, I suppose I could find out for sure how much my current system will cost to fix then just pay for £150 boiler insurance each year. Hmm.

macman

Don't even think about calling in BG. Get an independent CH engineer in to advise.
You haven't given the age or model of your existing boiler, but parts are usually available for boilers for many years after they go out of production. My combi is 11 years old and I can still get any parts I need easily.
10mm pipes mean you have a microbore system.