changing trvs

[novice1]

Have had a leak from a valve causing big cost for carpets etc (only part covered by insurance). Plumber said replace all trvs as they are 15 years old. Quoted about £500 plus valves. Fairly modern 15m system.
Questions:
1 - Do the valves tend to fail together, i.e is it wise to replace the lot now as I have to drain the whole system down?
2 - what is the way to do it? Is it turn off the outlet to the tank in loft, turn off CH boiler, open valves on all radiators (and boiler?) and drain from bottom point, replace trvs from top down, add fernox or equiv to header tank and refill slowly checking for leaks from bottom up?
3 - Do I need to do anything with the boiler?
4 - Any other tips on trv choices etc?
Any help gratefully received

 

[newbie1]

how many valves

 

[novice1]

twelve valves

 

[newbie1]

twelve valves means rather than mess around in future then change all at once as system will be drained anyway
boiler off or clock off isolate feed tank and drain then just replace each valve prob only days work though good trvs about 20quid less flash about 5-8 quid each

 

[novice1]

Thanks Newbie, very helpful.

 

[smoggs03]

stick some inhibitor in your header tank too!!when filling back up. oh and check header tank for debris before draining/ filling or a blockage is imminent

 

[novice1]

Thanks smoggs, will do.

 

[willing2learn]

Hi, a lot of the cost will depend on whether any of the pipework will have to be modified. This can turn a relatively straight forward job into a longer one

 

[novice1]

No. it's very straightfoward, modern house with standard pipework and easily accessible trvs. I'm weighing up whether to do it myself or to use a plumber. second estimate next week will help me decide!

 

[NickH]

Even "standard" pipework, whatever that is, can be a problem if you have no movement on it, like when its buried tightly in the concrete floor. Having said that, £500 labour seems possibly a bit steep.

 

[Aquarius]

Don't put trvs on all rads leave one rad without. Something I was taught when at college.

I fitted 10 trvs for a customer and charged £150 labour

 

[novice1]

Yes, standard pipework can mean a lot! It's all about 6inches long out of concrete floors so there's a degree of play in it all. The only time it's been touched (the house is under 20 years old) was to add the last lot of trvs which seemed a quick, easy job done when we had a shower and bathroom radiator fitted. I'm assuming most 15mm valves are going to be made to a standard size and generally easy to swap? They are called Giacomini for what that's worth!

 

[willing2learn]

It's more to do with how much the TRV will stick out the side of the rad. Extension pieces can be used though.. but obviously not if the new TRV sits too close to rad compared to old one.

 

[the baker]

No. it's very straightfoward, modern house with standard pipework and easily accessible trvs. I'm weighing up whether to do it myself or to use a plumber. second estimate next week will help me decide!

Do you have a mechanical bent, will household insurance company pay out if you inadvertently mess up? (a, big black mark on white carpet, smiley)

If you do mess up you wont be able to call upon the public liability insurance a professional should have.

Obviously its your choice.

Have you asked your friends to see if they have recently employed a person who did similar work and whom they are happy with?

There are loads of people out there who having been made redundant are doing their best to obtain new skills and gain employment.

Some unfortunates are spending thousands attending so called training establishments but do not leave the building competent to do the work you require.

Others have tried to advise you re the pit falls of changing radiator valves and from experience I know that removal of some valve tails can very difficult.

I would not advise one of my customers to simply change a single valve without giving serious consideration to changing all of the valves especially the age you said, was it fifteen years?

If you do fancy having a go why not wait until the summer when you will be under less pressure to get things going again.

Tim

PS forgot to say that if you do decide to do the job your self and wait till the summer you will be able to do the job in stages and so can keep poping back for advice

 

[novice1]

the baker ..... you make fair points and I don't want to do it but we have an insurance offer to settle at way less than half of the cost of replacement so I'm about £1900 out of pocket. Don't want to get into detail but a carpet used in all rooms of the house when stained will lead to insurance company only wanting to pay for damaged room, if it's the hall stairs and landing a new carpet won't match all the others! Amazing pitfalls on this insurance lark!
Appreciate your advice and likely to get a plumber to do it but need a recommendation which I'll seek.

 

[WHPES]

Depends on the existing connections. Sometimes I just undo the nuts, take off the old TRV valve and stick a new one and tighten the nuts back up, probably the easiest thing out and it takes longer to refill the system than do the job.

However if the old TRVs attach onto 3/4" tails, you've got to remove the old tails which can be a right pain, and replace them with 1/2" x 15mm tails.

Some older valves have smaller thread pitches which are different to the modern fittings and you've got to remove the olives and nuts.

I agree, £500 sounds a bit steep.

 

[derrybongo]

just a thought but would it be worth sticking in some descaler first just to get it through the system for a week or so prior to draining down and then refilling with inhibitor

 

[WHPES]

Depends if your system is dirty. If so you could use Fernox F3 but it is vital to ensure that you rinse it out several times to ensure there is no trace left in the system. It would normally be done using a powerflushing machine.

You'll need to open all the bleed valves in all the rads when draining off to ensure you get it all out, then refill, then drain out again.

PS if you are fitting lots of TRVs you must make sure that your system bypass valve is an automatic valve or you could end up with problems.

 

[bobpape]

The Baker described plumbers as being proffisionals..

Whilst we may behave proffisionally we are not professionals,

The same applies to the title engineer...

unless we have a degree we are not engineers

If you dont believe me try getting insured using the aforementioned as a job title.

 

[REDSAW]

The Baker described plumbers as being proffisionals..

Whilst we may behave proffisionally we are not professionals,

The same applies to the title engineer...

unless we have a degree we are not engineers

If you dont believe me try getting insured using the aforementioned as a job title.

is a car mechanic?

as i believe a 'proffesional' is when you make a living out of some thing ie, footballer, and i doubt not many of them even went to college.

only, down at my local car shop, it says 'dakin's motor engineer' and they have insurance for trade plates?

 

[peteheat]

Hi,

This thread makes for interesting reading, I never cease to be impressed by how some people can say one man's price is expensive having never seen the job

Maybe the man who took the time to carry out the survey has included power flushing, fernox etc but has not actually specified them because some consumers "switch off" when the tradesman starts to get technical.

As one who would not even offer a guide price over the telephone because I could be misleading the consumer I tip my hat to the expertise of those who can price a job "Blind" .