Upgrading / Thermostatic Valves for Radiators

Vote 4 Pedro

Hi,
I am thinking of getting the Thermostatic Valves for Radiators fitted in our 8 year old Bungalow with 15 rads,
It's not the best system in the world, Open system, Boiler is a Firebird 90s, 15 rads, no room stats just the main one on the boiler, it's not zoned, basically its all or nothing.
We are finding the water is very very hot and the rads mildly warm but not hot.
I know the system need up dating and proper balancing but we can not afford to get the hole system upgraded so I'm going to do it in stages

What i would like to know is what should be done first, as I said money is tight so it would have to be done a bit at a time and hopefully give us a warmer house, would the Thermostatic Valves for Radiators be the place to start.
Advise much appreciated, Thanks.

heinbloed

The maintenance of the boiler would be the first thing to look at.
Shop around for fuel prices, weeks before running dry.

Balancing the CH system is the next issue, if intending to install TRVs include this. Ask your engineer to optimise the system.

Vote 4 Pedro

heinbloed wrote: »

The maintenance of the boiler would be the first thing to look at.
Shop around for fuel prices, weeks before running dry.

Yer the boiler is fully serviced and we do let the oil run nearly out before reordering,

Joey the lips

No the thermostatic valves are not the place to start. They will not improve the heat to the rads just regulate and turn it down which by the sounds of your house you do not need.

I am randomly guessing your boiler needs a service and perhaps the radiators need a good power flushing. This would be roughly where i start.

Vote 4 Pedro

Hi,
The boiler was just serviced 2 weeks ago so that should be fine.

heinbloed

Well, then the TRVs would be the next step. Fix them in the best possible position(not at the bottom but at the top of the radiator).
After this balance the system.
After balancing reduce the flow temperature to the minimum needed, not going below the minimum stated in the boiler's manual.

If the budget allows for it install an intelligent A-rated pump. These pumps repay themself by the saved electricity consumption (when compared to the old mill wheels) within 2-3 years.

Vote 4 Pedro

Thanks heinbloed,
but what is a intelligent A-rated pump, apart from it been "A" rated for energy what's the intelligent side of it.

heinbloed

The intelligent pump meassures the pressure before and after the pump, the resulting difference between these two pressures will then cause an increase or decrease the of speed of the intelligent pump.
An automatic pump, fully modulating.

The changing hydraulic pressure during the normal operating of a CH system (individual radiators are turned on or off) asks for a changing pump operation.

The standard (A-rated) pumps work only step for step, are stepwise modulating. Usually these work harder than necessary to get the required minimum of water circulated.

Check the home pages of Wilo, Danfos, Grundfos, etc....Laing (now: Lowara) are the frontrunners in developing high quality products.

d o'c

Vote 4 Pedro wrote: »

We are finding the water is very very hot and the rads mildly warm but not hot.

I would be checking the existing system before buying TRVs just yet, with the aim to get the rads hot. as mentioned TRVs will only regulate, but if the heat isn't there in the first place, you won't see any gains overall.

TRVs basically have a plunger that blocks the flow of hot water through the radiator when the temperature sensed by the head is reached, when the temperature in the room drops, the head releases tension on the pluger pin, the rad heats up.

No matter how basic the current system is, I'd be looking to see why your rads are only getting mildly warm, instead of hot..
When your at the stage where you can say all your rads are getting hot, then look into regulation and fit TRVs.

Has the system performed better in the past? Or was it always this way.
You've serviced the boiler, but is it powerful enough?
Are you loosing heat on the runs ( pipe lagged?)
Do you have signs of airlock? (cold patches)

Vote 4 Pedro

d o'c wrote: »

No matter how basic the current system is, I'd be looking to see why your rads are only getting mildly warm, instead of hot..
When your at the stage where you can say all your rads are getting hot, then look into regulation and fit TRVs.

Has the system performed better in the past? Or was it always this way.
You've serviced the boiler, but is it powerful enough?
Are you loosing heat on the runs ( pipe lagged?)
Do you have signs of airlock? (cold patches)

The boiler has always been this way, It's not that the rads don't get hot, but I think there is too many rads on the system.

The boiler service engineer said he thought it was running fine, but I got a very reputable plumber out to look at the system and his opinion was that the boiler should be big/powerful enough
to run all the rads but it had been plumbed wrong in the first place and needed updating mainly to Zone the system and balance the system between the rads and hot water.
but all the pipes in the system are under ground so it's not going to be easy.

All the pipes are underground so although they were in the basic gray pipe insulating foam we can not do any more about it.

There are cold patches in the system, We have 15 rads in total, 4 are completely off, 2 are set very low to allow the heat where we need it.

The plumber said that after he had finished all the work the house would be a lot better and all rads would be warm, The problem is that the floor will have to come up in the utility room to do the work,
It's a job that he has to do all in the one job and we have to save a while for it so i though the TRV's might help in the mean time, as they would have to be fitted at some point anyway.

heinbloed

...The problem is that the floor will have to come up in the utility room to do the work,....

This might be a wrong information he's giving to you. He might be looking for a big job to make a big profit.
The energy demand must be calculated according to EN 12831, before he doesn't do this or asks someone competent to do this don't trust this man.

That 15 radiators don't get warm/hot with the Irish standard boiler sizing (usually two or three times bigger than needed) is strange. What type of boiler is installed, what is the flow and return temperature?
Have you got a service protocol ?


CH pipes can be laid on walls, on floors, on ceilings, in walls, in ceilings, above ceilings. There is no need to rip out anything when installing a new CH distribution.

Vote 4 Pedro

The Boiler is in the utility room, so in the hot press, (well it's right next to it)
All the pipe work from the boiler to rads and hot water cylinder are under the utility floor,
The pipes come out of the boiler, the pump, then they go straight down under the floor and come out up the side of the water cylinder, about 6 feet away,

The Plumber is a decent sort, you can tell, he was recommend buy quite a few local people and I've been to there houses and looked at some work,
talked to the people and he came out top compared with some other plumbers i have had dealings with, I might be wrong but that's why i got other peoples opinions.

heinbloed

Obviously he didn't do his job properly, otherwise we wouldn't be discussing here the problems you have. Was the energy demand calculated, have you seen the calculation sheet?

This demand calculation ( EN12831 ) is part of the legally binding building regulations as far as I know.

d o'c

if it's fully pumped system open vent (pumped DHW coil) enquire with a plumber if you can fit a handvalve to the hot water cylinder coil. Sound like you have way too much bias toward the DHW, I'd say a lot of your heat is headed to header tank in the attic. have a look at the attic tank when the sytem is hot,and see if you have alot of steam water coming from the vent.If it can be fitted you may find having it just slightly open will be enough to heat the DHW

I would have thought only the rad pipes would be buried under the floor,so I can't see how you need to rip up the floor.

cool patches toward top of rads will be air
cool patches at the bottom can be a sign of sludge.