TRV

[sam19]

Hi
i have a central heating system with the cylinder in the airing cupboard

i have 10 radiators all with manual valves

i want to change to TRV so that i can regulate temperature in te bed rooms which sometimes becomes hot

i am employing a plumber/ heating engineer to do the job

reading through the internet i feel to descale the system and put in inhibitor as water in the system is dark

i have bought some Scalemaster SM4 to do this

my engineer tells me that it is difficult to get these types of substances out once put it in unless powerflush and advises me that not to bother with it

However, salesman in the shop which sells these substances tells me unless you get rid of these scales and put in an inhibitor the TRV may not work properly

i am confused as to which one to follow

Many thanks in advance for advise

sam

 

[Agile]

On this occasion the salesman is more right than the engineer.

But he should have sold you a leading brand of inhibitor like Fernox or Sentinel.

I suspect you dont want to pay your engineer for treating with the chemical and he tells you that because he knows you dont want to pay him for whats involved in doing it properly.

Tony

 

[kevplumb]

get some cleanser in the system and give it a good run


only time you might have probs getting it out is with drop fed rads and there is a way round that

 

[sam19]

it is not that i dont want to pay

engineer says it is not needed

to do it proprly he says it needs powerflush and it will take a day and will cost £300 and he says it is unnessary as i have a 15 year old potterton boiler and the channels are bigger and it would not get blocked.
he tells me if change to a combi boiler it is will be essential to powerflush and it can be done at that time. but i am worried about the PROPER FUNCTIONING OF TRV

i am not sure but he mentioned some thing like my system is a drop fed system

THANKS AGAIN

 

[kevplumb]

put it in on a 15 yo system it will deffo clear some of the accumulated carp out

and as tony says get a decent brand

 

[sam19]

Thanks Kev

i will get a good descaler

my radiators are drop fed radiators

how to get it out of the system

sam

 

[kevplumb]

once its in and done the biz

drain as best you can , refill , bleed , run the system 10 / 15 mins

switch off and repeat

easier than draining rads

unless you have any of these



View media item 17276

 

[Agile]

I would use dynamic flushing!

Thats a term I coined about 10 years ago which was then copied by Camco including my description!

You run the heating with all rads on and then bleed about 3-4 litres/minute to drain and continue for about 40-90 minutes when the water runs clear.

It works well with drop fed rads. But you can turn off the other rads for a while if you wanted to give extra flushing to just those.

Tony