Heating system drain, new valves, flush and balance

[Onelasttime]

Anyone have a rough idea what the cost in London might be to do this job? I've contacted our local Vaillant engineer to see if wants the job but be good to have a ball park figure in mind.

Bit of boring backstory: When we moved to the new house back in Feb we noticed two TRVs didn't work and the radiator in the kitchen never really got, hot just warm.

We ended up having to use the lockshield to shut off the rad in daughter's room because it got too hot. Then we used the lockshields on other rads because we didn't know any better having only had a combi boiler and wireless thermostat in the old house. Needless to say, a couple of lockshields are now prone to slight leaking.

The boiler was serviced in Dec last year and had a new pump fitted and is working fine for hot water, although it does date to 2005.

I just want to prepare the heating for when we start using it, which will be very soon.

Is draining, replacing valves and flushing the way to go?

[lewie]

Not sure how capable you are but that’s a pretty simple job

[Onelasttime]

Not sure how capable you are but that’s a pretty simple job

I thank you for your faith in my heating engineer skills, but I will not be going near it.

This is a job for someone trained and competent, of which I am neither

[noTAGlove]

heating engineer skills

Spent 4 years at uni getting an engineering degree, then it took me several years of effort and focus including report and interviews to become a Chartered Engineer.

Who knew with a bit of spannering I could have saved myself 10 years of hard graft.

[blackal]

Spent 4 years at uni getting an engineering degree, then it took me several years of effort and focus including report and interviews to become a Chartered Engineer.

Who knew with a bit of spannering I could have saved myself 10 years of hard graft.

If humblebragging was going to solve his problem..................

we could shut the thread down now!

[noTAGlove]

If humblebragging was going to solve his problem..................

we could shut the thread down now!

I saw nothing in what I said as humble, and I a fooking brilliant engineer, right. Except when it come to wielding a spanner to repair washing machines and radiators.

I am off to the What Do You Drive Thread to post another Maserati (on monthly payments, leased of course).

[Onelasttime]

If humblebragging was going to solve his problem..................

we could shut the thread down now!

He's not wrong though. This is why I'm going nowhere near it. And probably why I only drive a 2009 Mazda 6 …

Some useful above, thanks. Good to know I'm not barking up the wrong tree, but maybe need to find a bigger tree, e.g. fit new rads at the same time.

If I get all new rads now, will it be a fairly straightforward job to fit a new boiler next year? Is there any advantage to doing it all at once?

I'm weeping thinking about the cost of all this.

[johnboy9876]

It all depends on the size of your house (and heating system But if it's an average 3 bed, I don't think you will get much change from £1K

I think that the cost (and effectiveness) would depend on the age of the radiators (because replacing them might be cheaper than flushing them through and trying to fit new valves to them, in labour cost terms. Perhaps ask the plumber that you get to quote you what they think

Might be best to measure your current radiators and do a rough calculation on it. The average double rad is around £70, the thermostatic valve and lock valve £20 for the pair, to give you a guide

Hope this helps
John

[lewie]

Might be best to measure your current radiators and do a rough calculation on it. The average double rad is around £70, the thermostatic valve and lock valve £20 for the pair, to give you a guide

Hope this helps
John

I doubt you’ll get prices like that quoted by a fitter

[Onelasttime]

To answer some questions, it’s a three bed with 7 rads.

The radiator in daughter’s room didn’t respond to the TRV so her room was too hot when the heating was on, hence us turning it off at the lock shield. Not ideal I know.

The heating hasn’t been on since March but hot water has been on twice a day.

[walkerwek1958]

Whilst the system is drained down it makes sense to replace all the Thermostat radiator valves, this gives the benefit of knowing they're all new and you get the peace of mind that they should function Ok for a good few years. I bit that bullet when moving into my current property a couple of years back and it paid off.

[Kingstepper]

If the heating is off but the radiators heat up I'd bet a scabby Seiko that your diverter valve is stuck. When the boiler switches on to heat water it's also sending hot water around the rads.

It's supposed to switch between water and heating or somewhere in between when the system demands both, hence it's called 3-way.

Old ones are manual and are literally a levered valve, usually left on the 'in between' setting.

Modern ones are powered by an electrical motor. Switched by the programmer on demand.

Good news.. they are not expensive to replace except where a manual diverter needs replacing with an electrical one.

Solving a problem that doesn't exist. Where has OP said rads heat up when heating off?

[Kingstepper]

Here

Nothing there.

[Onelasttime]

Here

To answer some questions, it’s a three bed with 7 rads.

The radiator in daughter’s room didn’t respond to the TRV so her room was too hot when the heating was on, hence us turning it off at the lock shield. Not ideal I know.

The heating hasn’t been on since March but hot water has been on twice a day.

HERE

[johnboy9876]

I doubt you’ll get prices like that quoted by a fitter

Exactly!

Use a bit of time to research prices and buy the materials yourself, decent savings to be had. Then just pay for the labour

[MCFastybloke]

[QUOTE=johnboy9876;6080210]Exactly!

Use a bit of time to research prices and buy the materials yourself, decent savings to be had. Then just pay for the labour[/QUOTE


A number of lads, my self included wont touch labour only work, you took some profit from my table and you are low priority. This may change round as it suits us when the job,or if the job get a bit slacker.

Also warranty issues can creep in later,

Rads not warm -You
Valves faulty-me
You fitted it wrong,you
I will look but its not free-me

This is an abridged version

Doesnt usually end well.

[bobc]

Boiler serviced with full flush of system and new radiator fitted £300. It's wonderful living in rural Lincolnshire where you know the local tradesmen .

[blackal]

Boiler serviced with full flush of system and new radiator fitted £300. It's wonderful living in rural Lincolnshire where you know the local tradesmen .

A day's rate, similar in concept to the OP's scope.

[Craizeehair]

If you’re talking about a full powerflush then the average price for an independent will likely be around £400-£600. If you don’t have a magnetic system filter you may want to consider adding one, if fitted at the same time as the powerflush then depending on the type of filter, that could be around an extra £150.

Cost to replace the TRVs and lock shields can vary, you could spend £10 on a pair, or £30 a pair for a higher regarded make of valve, then you will have the labour cost to carry out the replacements.

You should be able to get all that done for around a grand, give or take, if all done at once.

If the radiators heat up top to bottom and generally all get nice and hot, with no nuisance lockout of the boiler, I would suggest thinking twice about paying big money for a full powerflush. Pumps can be an issue but you have a new one, hopefully that rules that out.

I’d probably be looking at getting the faulty radiator valves changed, possibly all of them if you’re looking for belt and braces peace of mind. A decent heating ENGINEER should be able to diagnose what’s causing the kitchen rad to not heat properly, this could just be an issue with the TRV or lockshield but shouldn’t be hard to diagnose, but bear in mind it’s impossible to day without seeing it. I would think a rough estimate would be in the £500 ball park for that.

I would definitely get someone trustworthy in to take a look and give you the right advice for you.

[Onelasttime]

If you’re talking about a full powerflush then the average price for an independent will likely be around £400-£600. If you don’t have a magnetic system filter you may want to consider adding one, if fitted at the same time as the powerflush then depending on the type of filter, that could be around an extra £150.

Cost to replace the TRVs and lock shields can vary, you could spend £10 on a pair, or £30 a pair for a higher regarded make of valve, then you will have the labour cost to carry out the replacements.

You should be able to get all that done for around a grand, give or take, if all done at once.

If the radiators heat up top to bottom and generally all get nice and hot, with no nuisance lockout of the boiler, I would suggest thinking twice about paying big money for a full powerflush. Pumps can be an issue but you have a new one, hopefully that rules that out.

I’d probably be looking at getting the faulty radiator valves changed, possibly all of them if you’re looking for belt and braces peace of mind. A decent heating ENGINEER should be able to diagnose what’s causing the kitchen rad to not heat properly, this could just be an issue with the TRV or lockshield but shouldn’t be hard to diagnose, but bear in mind it’s impossible to day without seeing it. I would think a rough estimate would be in the £500 ball park for that.

I would definitely get someone trustworthy in to take a look and give you the right advice for you.

Very helpful. Thank you.

[Mr Pointy]

You may be able to get the TRVs working if they have just siezed up. If you remove the TRV head you should see a pin sticking up from the valve body & it's this that needs freeing up. Try increasing amounts of persuasion from pressing it to a gentle tap with a soft faced hammer to see if it moves.

https://www.youtube.com/watch?v=xFLkgkoAtPI

[wileeeeeey]

If one isn't included I'd get a magnaclean fitted too at the same time.

Unit is about £90 from Screwfix or OEMs do their own.