New trv advice please

[marb]

I have just had new TRVs fitted. Now as I am not used to using them, I would like to get the best out of them along with my combi boiler.

Up to now I have been having the boiler set at economy (middle setting) and having it come on and off at long-ish intervals through the evening when we are in. As we also have a coal fire the room we are in gets warm enough without them but sometimes we need a burst of heat here and there depending on how cold it is. We have no room stat. The TRVs are Bulldog bio-directional.

I turned the unused front room down to 1 on the setting but it was still heating up hot despite the TRV which should keep it off. The room was def at reasonable temp so why it came on I don't understand. This also happened with our room with the coal fire. Turned the TRV right down but still came on hot with the fire lit and the room at 21oC. This is only after a first night of using them so perhaps they have to settle down a bit.

What I would like to know is the best setting on the boiler as well how much we have it on. The plumber who fitted them said its best to have the boiler on full and the TRVs will do the rest. Is it more economical to have it come on and off or leave on and let the house stay at even temp ?

Cheers.

 

[dcawkwell]

You need a room thermostat.
Otherwise the boiler pumps away even when the house is hot.
A TRV in the room set a one should just keep the room just above cold.
TRV isn't working or there is some other problem.
Generally TRV are more trouble than they are worth or so I find.

 

[marb]

Yes but if I only have the boiler coming on at intervals that should be better. Plenty of energy saving tips always state the use of TVRs. They have to be fitted by law when a heating system is installed so they must be doing something to save money.

 

[dcawkwell]

Yes but if I only have the boiler coming on at intervals that should be better. Plenty of energy saving tips always state the use of TVRs. They have to be fitted by law when a heating system is installed so they must be doing something to save money.

Yes but they don't mention when trv's break and need replacing paying a plumber to come around and replace one.
Or the fact that you can go into 90% of the houses with them and they are all wound right up to 5.
So much for eco. Just like get a condensing boiler. Sure it might be more economical running but is it really more economical when it will need replacing after about 10 years have gone through 2 or 3 fans and other parts in that time. Fuel for the repair engineers to get there and fix it. Compare that to mum mums old boiler that has needed a thermocouple in 40 years and will probably last another 40 years.

Get a wall thermostat it is far better than trv's and only costs £10.

 

[marb]

A room thermostat controls just one room. TRVs control individual rooms. The room thermostat will only sense the one rooms temp. If a TRV fails you just replace it. Even I can do that. My central heating is set to go on and off in intervals and running it like that is cheaper for us. With added TRVs it will be even cheaper.

 

[dcawkwell]

A room thermostat controls just one room. TRVs control individual rooms. The room thermostat will only sense the one rooms temp. If a TRV fails you just replace it. Even I can do that. My central heating is set to go on and off in intervals and running it like that is cheaper for us. With added TRVs it will be even cheaper.

A room thermostat is intended to be put in the hall or similar to measure and average temperature for the house and most importantly cut the boiler off when the house reaches temperature.

A boiler coming on and off in intervals is doing exactly what most modern heating systems try to avoid cycling of the boiler which is wasteful. The cooling and reheating of the boiler is wasteful. A modern boiler will work much better running continuously it will modulate down to meet the demand until the house reaches temperature.

 

[D_Hailsham]

We have no room stat.

Get one fitted!

I turned the unused front room down to 1 on the setting but it was still heating up hot despite the TRV which should keep it off. The room was def at reasonable temp so why it came on I don't understand. This also happened with our room with the coal fire. Turned the TRV right down but still came on hot with the fire lit and the room at 21oC. This is only after a first night of using them so perhaps they have to settle down a bit.

Sounds as if the plumber who installed the TRVs didn't bother to balance the system.

 

[marb]

No point getting a thermostat fitted. You are not supposed to have one in a room with a trv anyway. The only room we have not got a trv is the bathroom. He did stay until the rads all heated up when fitted. Some people make balancing out to be a dark art. He just told me to play around with them until i am happy.

 

[D_Hailsham]

No point getting a thermostat fitted. You are not supposed to have one in a room with a trv anyway.

There is a point in installing a thermostat: it will save you money by reducing your gas consumption

You can get round the problem of having a TRV on the rad where the stat is installed by setting the TRV to max.

Some people make balancing out to be a dark art. He just told me to play around with them until i am happy.

I wonder what he meant by 'playing around with them'? Was he talking about the TRVs? If so, he doesn't have the first idea how to balance a system.

 

[marb]

But if I have to have the TRV set to high in the room with the stat, I will have wasted money on that TRV as it becomes redundant. More money spent on a stat as well as having it fitted. Counter productive against saving on heating bills surely ? Again, TRVs do the same job as a stat BUT with individual rooms, not a general blanket setting.

My original concern though was why some of the rads are still coming on when set to 1. The upstairs were set to 1 but didn't come on. It doesn't seem consistent.

 

[JonCa]

Again, TRVs do the same job as a stat BUT with individual rooms, not a general blanket setting.
My original concern though was why some of the rads are still coming on when set to 1. The upstairs were set to 1 but didn't come on. It doesn't seem consistent.

TRV's regulate the heat input to a room from the rad they are controlling. A stat turns the boiler off when target temp achieved. similar function but there is a significant difference.

Sounds like :-
- - plumber did half a job, or is that all he was asked to do, and
- - your TRV's are not working properly.

 

[marb]

I asked him to fit the TRVs. He also set all the rads at 5 but did say to play around with them until happy. he also set the in flow smaller tps he fitted with the TRVs. We had a problem with the front room rad (see other post) getting cooler and cooler over time. I turned off all the other rads and it came through again only to slowly go back to cooler and cooler over time. He couldn't understand why it should do this with a sealed system. When we added a small kitchen rad a few weeks ago the problem was worse. Since the TRVs have been fitted , so far the problem seems to have been solved. To have the rad in the front room not come on unnecessarily I have to set it between frost and 1. If I spend any more money on my central heating it will defeat the object of saving minimal gas consumption. As it stands our bills are not too bad compared to the average household.

If it's a dooable job balancing your own rads, is there any online help for the novice ?

 

[JohnD]

did the person who fitted your TRVs and gave this poor advice appear to be competent and experienced, or was he a jobbing handyman?

You do need a room thermostat as well. I am amused that you argue against one and also complain about poor heating and expensive gas bills.

 

[JonCa]

We had a problem with the front room rad getting cooler and cooler over time. I turned off all the other rads and it came through again only to slowly go back to cooler and cooler over time.
When we added a small kitchen rad a few weeks ago the problem was worse.
Since the TRVs have been fitted , so far the problem seems to have been solved.
If it's a dooable job balancing your own rads, is there any online help for the novice ?

Read that thread, sounds like weak/slow pump, hot water rises cold falls so hot at top only suggests circulation to slow (eqiv to valves shut almost right down), with circulation to slow any sediment carried in the water will settle out and potentially obstruct flow further.

TRVs balance in a fashion, as one shuts down it improves the circulation available for the others. so they can appear to solve a low flow / balancing issue.

Sounds to me as if your pump is suspect, and that you do have some sludge around. so a filter Fernox TF1 or similar may be worthwhile.

Balancing and other bits - see //www.diynot.com/forums/plumbing/boiler-central-heating-faqs.175736/

 

[marb]

did the person who fitted your TRVs and gave this poor advice appear to be competent and experienced, or was he a jobbing handyman?

You do need a room thermostat as well. I am amused that you argue against one and also complain about poor heating and expensive gas bills.

At what point did I complain of high heating bills ? I said they were reasonable compared to the average.

The pump is fine and there was no sludge in the system when it was drained. Clean as a whistle. We had the Heatline 24 installed just over 2 years ago (by another engineer) and had it serviced in the second year (and it was mint then) This current plumber said there is no reason we shouldn't get 20 years out of the boiler.

The plumber is a one man business Gas Safe registered. Worked for a company for years and now gone solo, just started out. He was compitent to me. Did a good, clean job. Ditto for fitting the kitchen rad.