Time for a complete new heating system?

[silver1011]

I often read the many heating system threads on here with interest knowing my own system is getting on a bit.

 

Last night my third two-port motorised valve failed in as many years resulting in unwanted heating.

 

I'd hoped to get another winter out of the system but am now thinking I might take the plunge and get it done this summer.

 

I'll start phoning around next week for quotes and further advice.

 

The boiler (Ideal Classic) is 20 years old this year and the radiator system is microbore (this is 100% going, being replaced with copper pipes). I have cold radiators despite several power-flushes and a Magnaflow.

 

Two questions:

 

1) Should I get a combi (family of 4 with 15 radiators inc. 2 towel rails, two pump fed showers, one bath)?

 

2) Roughly how much am I looking at? I appreciate it is impossible to be accurate, just hoping for ball-park i.e. £3K / £5K / £10K etc.

 

- New boiler (combi if suitable), sick of running out of hot water, happy to overspec if it gives it an easier life.

- New controller and thermostat, current ones are as old as the boiler.

- Removal of current hot water system (tank in airing cupboard, cold water tank in loft?)

- 13 new radiators (towel rails can stay)

- Replace all radiator feeds from plastic microbore with copper (current pipes routed into the walls with concrete ground floor so downstairs will need routing along internal walls and boxed-in)

- Anything else I've missed?

 

A few pictures to help...

 

Been a good boiler, never broken down. Has a pilot light though so not particularly efficient?

 

 

Hot water tank with the motorised valves

 

 

Horrid microbore, most houses on the estate have had it ripped out, we are one of the last. Inaccessible as it is fed into the walls right above concrete floor...

 

 

Old controls and thermostat...

 

 

 

Any help would be appreciated!

Edited 10 July, 2016 by silver1011

[Rustynuts]

Looking at that pic, it appears as though the CH valve is a Honeywell pattern one while the DHW is a Drayton. The motors in the Honeywell valve can jam sometimes and stick the valve open. Ia motor replacement is fairly straight forward for a temporary fix.

Edited 10 July, 2016 by Rustynuts

[silver1011]

I've a plumber mate coming on Thursday to replace it, he mentioned having to drain and refill the system, but this wasn't needed for the last two I've had changed in the past.

 

I'll be asking him for advice on replacing the whole lot, mainly down to the microbore and cold radiators.

 

A little more online research suggests a combi might not be ideal for our needs. Great for instant hot water (a frustration with the current system) but not so good in situations of high demand i.e. two showers running at once.

Edited 10 July, 2016 by silver1011

[silver1011]

They've both been replaced over the recent few years, I still have the box for the last one...

 

[bigjohn]

I've a plumber mate coming on Thursday to replace it, he mentioned having to drain and refill the system, but this wasn't needed for the last two I've had changed in the past.

 

I'll be asking him for advice on replacing the whole lot, mainly down to the microbore and cold radiators.

 

A little more online research suggests a combi might not be ideal for our needs. Great for instant hot water (a frustration with the current system) but not so good in situations of high demand i.e. two showers running at once.

 

If you replace the whole valve you will need to drain the system. Usually it's the motor that fails easy/cheap fix without draining the system

 

Search for "replacement synchronous motor for motorised valve"

[Rustynuts]

Yep, 2 screws and 2 wires to disconnect, then refit new motor and reconnect. Takes 10 minutes on a Honeywell one. I'm guessing though that someone used a Honeywell "copy" valve which is why it's failed again so quickly.

[Towny]

Maybe look into getting bigger (for demand purposes) a high pressure cylinder. You can take the pumps off the showers then as well. I would advise against a combo on the basis of if it breaks you'll have no heating or hot water. With a cylinder it has an immersion heater so you can still have a shower/get a wash, and you could just all cuddle together to keep warm!

[silver1011]

Yeah, the more I read up on it the more a traditional non-combi boiler makes sense.

 

Because of the failed motorised valve I've had to shut off the boiler and turn off the pump next to the hot water tank (constantly running).

 

Luckily we have an electric heater in the top of the tank so still have hot water!

Edited 10 July, 2016 by silver1011

[Robjon]

I'm guessing though that someone used a Honeywell "copy" valve which is why it's failed again so quickly.

 

This would be my guess as well.  The Honeywell valve in my system lasted more than 20 years.

[bigjohn]

Yep, 2 screws and 2 wires to disconnect, then refit new motor and reconnect. Takes 10 minutes on a Honeywell one. I'm guessing though that someone used a Honeywell "copy" valve which is why it's failed again so quickly.

 

It's a surprisingly common fault ( well every 5 years)  - It;s so quick, easy and cheap I keep a spare in my "bits" drawer

[Macdemon]

I am NOT a plumber, but am speaking from someone who has had issues with my own central heating system over the past few years.

 

Yes, go for a combi and the more powerful the better (better flow rate) so if you need both showers at the same time and a hot tap running in the kitchen it can cope easily.

 

You need to find out your water pressure before the boiler power can be determined, so talk to a plumber who can assist in this issue.

 

Forget power flushes, as all it will do is move the 'sludge' around your heating system. 

 

Don't bother with a central thermostat, get TRVs' fitted to all the radiators and that will be much more efficient.

 

TRVs' are thermostatic radiator valves and control the heat to an individual radiator.

 

 

This means in rooms your not using, you can turn down the heat in the winter and save money 

 

By fitting new copper pipework AND replacing the rads will mean a lot of the 'sludge' in your system will be erradicated 

 

With regards to budget, and being unsure of how large your property is, but maybe budget for £7k or more, this is a ballpark figure based on personal experience.

 

Hope I have over quoted that figure, and maybe a qualified professional can point us all in the right direction.  

Edited 10 July, 2016 by Macdemon

[Rustynuts]

Just to clarify a couple of points there. A combi is limited to how much hot water it can produce in 2 ways. First, the available flow and pressure, second, the gas input. Essentially, if there's insufficient of any then there'll not be sufficient hot water. If you demand too much hot water and the combi can't keep up then it's not going to work. If your demand outstrips the mains water capabilities then it's not going to work.

 

As for room thermostats, they are a Building Regulations requirement. You must install a room stat (usually in the coldest place in the house) and also TRVs to control other areas.

 

A proper powerflush will discharge the sludge out of the system (not to be confused with just adding a cleanser to the system).

[silver1011]

Cheers guys.

 

A few years ago I removed all of the downstairs radiators, took them out into the back garden and flushed them all through. The amount of thick black sludge in each one was horrific.

 

Unfortunately it made very little difference, the same cold radiators remained cold.

 

Once the radiators were off I opened the valves to check the water flow, it was pretty poor, barely a dribble on some. I suspect the microbore itself is partially blocked and or the manifolds.

 

I then had the Magnaflow fitted at the same time as a proper power flush (a stand alone machine and a radiator vibrator). Again no difference.

 

This is why I'm now going down the route of complete new radiators and more importantly replacing the microbore with proper sized copper pipes.

 

Once you go to this level it also makes sense to renew the boiler too.

[silver1011]

With regards to budget, and being unsure of how large your property is, but maybe budget for £7k or more, this is a ballpark figure based on personal experience.

 

Hope I have over quoted that figure, and maybe a qualified professional can point us all in the right direction.  

 

Ouch 

 

I was trying to play it out in my head...

 

£1K for a new boiler

£1K for new radiators and valves

£1K for new unvented hot water tank, copper pipe and other materials

£1K labour (£25/hour x8 hours/day for 5 days)

 

£4-5K seems fair, but as I'm no plumber either it is all complete guesswork!

[bigjohn]

Cheers guys.

 

A few years ago I removed all of the downstairs radiators, took them out into the back garden and flushed them all through. The amount of thick black sludge in each one was horrific.

 

Unfortunately it made very little difference, the same cold radiators remained cold.

a

Once the radiators were off I opened the valves to check the water flow, it was pretty poor, barely a dribble on some. I suspect the microbore itself is partially blocked and or the manifolds.

 

I then had the Magnaflow fitted at the same time as a proper power flush (a stand alone machine and a radiator vibrator). Again no difference.

 

This is why I'm now going down the route of complete new radiators and more importantly replacing the microbore with proper sized copper pipes.

 

Once you go to this level it also makes sense to renew the boiler too.

 

Did you ever change the pump?

Made a huge difference when I changed mine a few years ago. I also put in a system flush (can't remember what it was called - [EDIT] photo attached) recommended by my heating engineer - on the bottle it said leave in for a few hours but the engineer said leave it in for a week. After draining and flushing with water until it ran clear - I then filled with an inhibitor and an anti kettle .  

 

Apart from changing a couple of valve motors (see above) the whole system has been perfect (silent + hot rads) since

Edited 10 July, 2016 by bigjohn

[Macdemon]

Ouch 

 

I was trying to play it out in my head...

 

£1K for a new boiler

£1K for new radiators and valves

£1K for new unvented hot water tank, copper pipe and other materials

£1K labour (£25/hour x8 hours/day for 5 days)

 

£4-5K seems fair, but as I'm no plumber either it is all complete guesswork!

 

 

A combi boiler for a grand..................get me a couple would you

 

Labour is the killer, and I think it will be significantly more than you anticipate.

 

I maybe wrong though, and I hope I am.

[silver1011]

No, must admit, never changed the pump. Might be a good idea. When trying to turn it off last night (the failure of the motorised valve seems to have resulted in the pump running all the time) I did notice that there was a speed wheel on it. Currently sat halfway between 2 and 3 (only way to turn it off, lol), perhaps turning it up to max might help to test it.

[silver1011]

A combi boiler for a grand..................get me a couple would you

 

Labour is the killer, and I think it will be significantly more than you anticipate.

 

I maybe wrong though, and I hope I am.

 

I'm now leaning back towards a non-combi boiler, still on the fence though 

 

You might be right about the labour, another £10 / hour soon sees the £1K turn to £1,400!

 

Not sure what the going rate is these days.

[Ade VRS]

You could save yourself some labour costs by pulling up carpets/floorboards etc where needed. I did this in my old house and it shaved a fair chunk off the labour and finish times.

[silver1011]

Good point, this will surely save the plumber lots of time.

 

One big downside I'd not figured in, moving beds, carpets, furniture etc. Booo!

 

I'll likely have to have new flooring too. There isn't much that annoys me but creaky floors under carpet is one 

[Macdemon]

I'm now leaning back towards a non-combi boiler, still on the fence though 

 

You might be right about the labour, another £10 / hour soon sees the £1K turn to £1,400!

 

Not sure what the going rate is these days.

 

Kitten and I have a condensing boiler at the moment, but want to change it to a combo in Sept.

 

Generally speaking, they are more expensive to install and don't last as long as a condenser boiler, but they are MUCH more energy efficient. 

Edited 10 July, 2016 by Macdemon

[RapidPaul]

Kitten and I have a condensing boiler at the moment, but want to change it to a combo in Sept.

Generally speaking, they are more expensive to install and don't last as long as a condenser boiler, but they are MUCH more energy efficient.

I thought pretty much all boilers are condensers these days? The choice is between combi condenser or heat only condenser with a seperate cylinder for hot water storage.

[VWD]

no coment on technical aspect of non combi or combi. But we had our old Baxi replaced by Combi couple of years ago and there's a big saving  in cost since. Problem is that how much of that is due to heat saving in ground floor, since the 18" square hole in the kitchen wall was bricked up. Bloke who fitted ours ( no axe to grind ,since ours was fitted by landlord=LA )

suggested that we would find savings in that we only pay for hot water used, but that flow rate is dependant on how any taps in use. My one gripe is that max tmp on hot water is 60C ,in system, but that is dependant on system pressure. ( nominaly 2 bar ,but since i believe system compensates for any air in system, that can fall and needs to be checked).Other gripe is that system being basic , has only system time clock( and that's on system in bedroom), although we have found that house is better regulated and use of thermostat is sufficient.

But, there's only two of us in the house ,WRT use of hot water -morning wash and dishes. Any other washing ,and  electric shower gets used . looking at the two showers .

Combi is pressurised, without tank- is heat only just tank and non pressurised ?

Edited 10 July, 2016 by VWD

[Macdemon]

I thought pretty much all boilers are condensers these days? The choice is between combi condenser or heat only condenser with a seperate cylinder for hot water storage.

 

 

Combi and condensers are different systems, unless Im labouring under a misapprehension. 

[Rustynuts]

Any boiler sold or fitted must now be a high efficiency boiler. Essentially the only way to achieve the efficiency required is by condensing technology, so irrespective of combi, standalone, or any other type of boiler, it would now have to be condensing.

So a combi boiler as it used to be some years ago is now a condensing combi, and a system boiler is also now a condensing boiler.