Hello! I have a new problem I was hoping someone might be kind enough to offer advice on! A large house with lots of radiators, built in around the 1990s has just had a brand new boiler fitted, after being left without any heating or hot water for two months. Prior to that two months, the CH and HW worked fine on all rads. With the new boiler fired up, there has been some odd problems with the radiators. Some work very well, some are lukewarm, and some don't come on at all. After trying to release air bubbles and after a re-commission of the boiler, some of the radiators that worked earlier have stopped working, or have become luke warm, some of the radiators are still scorching hot. In addition, quite a few of the TRVs which are all drayton TRV4s, are starting to lose their heads, with the plastic crumbling. What could be the cause of the radiator problem? I'm wondering: (a) whether the crumbling TRV heads is an indication that there may be a valve problem with many of them (I noticed on a few radiators, a difference in setting the TRV to max vs 4 was the same as on or off - dont know if that means a faulty valve, or that the flow needs adjusting with a drayton tool). I understand that Drayton TRV4 heads tend to go often, but do the lockshields and valve bodies tend to stop working too? Replacing all valves everywhere seems a bit drastic, but if its necessary, its necessary i suppose. Would anyone recommend TRV4s again, which will cost an arm and a leg, or an alternative? How much might one expect replacing valves on 26 radiators to cost roughly? (b) whether having left the system alone for a couple of months, sediment may have settled and formed some sludgy blockage which moved around a bit between the first and second attempt at firing the system up - to explain why some radiators that were working, seemed to stop. When the system was drained, the water didnt seem particularly groggy at all, although when attempting to add some flushing liquids to an upstairs rad after draining the system, we were surprised to find that the rad seemed to have held water still. If this is the case, is a powerflush the only (expensive) solution? (c) Does it make sense to leave the cleaning detergent in the system for a couple of days, and to let it run through some heating and cooling cycles in the hope that if there are air bubbles, or sediment causing the problem, these might be resolved? (d) any other suggestions?? Many thanks in advance, for anyone who made it through all those questions and more thanks to anyone who might be able to help!
I'm guessing the new boiler is a condensing type? A good system clean should have been part of the install - not just to protect the boiler itself, but also to ensure it is warranted by the manufacturer (almost certainly a condition...) Anyhoo, TRV heads do tend to fail after around 12+ years. If you unscrew the head you may find that the 'pin' inside it sticking out a lot more than a 'good' head. Ergo it's turning your rad offski all the time. You can test the actual valves by pressing the metal pin on them down firmly - they should move around 5mm in, and pop cleanly out when released. In this case, all you need are new heads. With the TRV heads removed, do the rads now come on? In general, it's likely your issues are a combination of bust TRV heads, air locks, possibly a wee bit of sediment blocking the flow in an almost-closed valve. In any event, your system should have been cleaned. Do you have a magnetic filter fitted?
it is a condensing type yes. the installer i think was trying to clean it when he started having problems with applying the cleaning chemicals. hes employed to install only, so might not try to do anything else, which means arranging for someone else to come on - will call the company tomorrow to check. ill check a few more of the trv's, so far the ones i have tested seem to spring back nicely. one problem radiator that was cold, we isolated, and started draining. when we did, it started warming up, which i was told likely meant that the trv wasnt closing isolating properly, and that the lockshield was blocked, and not allowing a return. for the couple of problem rads where we did remove the trv's, the rads did not come on. is a system clean essentially: (1) drain, (2) refill with cleaning chemicals added, (3) drain, (4) refill with anti corrosive chemicals added? not aware of a magnetic filter!
Definitely get a magnetic filter fitted, like Magnaclean or smilar, once you put in X800, filter will need cleaning several times. Drain down system, refill & then pour some Sentinel X800 cleaner in the system, might need two bottles if a very large system. It can be left in for a extended period of time without affecting system, should notice an improvement within hours. http://www.sentinelprotects.com/uk/...systems/sentinel-x800-jetflo-ultimate-cleaner http://www.sentinelprotects.com/sites/default/files/fact-sheets/PF_X800Jetflo_5_EN.pdf When you come to remove X800, you'll need to flush system a couple of times, I ended up doing it three times here, before water was clear, then reill & add Sentinel X100 inhibitor, again might need two bottles.
If you fit Magnaclean filter first, you can then add the X800 via the filter. Easier way to dose system.
thanks for this. is there any particular model of the magnaclean filter you would recomend? is it something easy to fit that a maybe 4/10 skilled DIYer could do?
I used a Magnaclean as magnet is inside which I prefer, there are models like Spirotech MB3 which has the magnet fitted externally, some peeps have had the magnet drop off, as to fitting it's nearly identical between makes, & I prefer to fit on the heating return, as your catching the crud before it goes back through the pump. See what others recommend.
magnaclean ordered - will try to fit this sunday. will look to replace gland seals too in the hope that they may have been causing the heads to fail. incidentally, would you recommend like-for-like trv head replacements, or is there a more affordable generic type that would work just as well? although i am a fan of drayton and in particular their customer service, the heads are a bit pricey.
Drayton TRV4 are the rolls royce of trv's,one of the few A rated for efficiency, advantage of a liquid sensor, whereas other have a wax sensor Always been my favourite,have hardly changed in 23 years they been around,the newer TRV4's have a bi-directional valve body. What you spend on a replacement head, from £15 upwards, you could buy a complete TRV4 (white head) for £17:99p or £19:99p for (chrome head), with a new warrenty at Wickes. http://www.wickes.co.uk/Drayton-TRV4-White-Angled-15mm/p/118647
Thinking about problem, you could use Drayton TRV4 downstairs & something cheaper upstairs out of sight.
yes agreed. on cleaning the system, im hyoping a powerflush wont be necessary, but think that might be wishful thinking given about a quarter of the radiators arent working. generally speaking, would a magnaclean and chemicals clean out most sludge and how often is a powerflush necessary?
A mansion! Missed that figure 26, in op first post. Need a good size boiler to run that lot, plus they will need balancing.
its a worcester 42 kw boiler.. lots of small radiators! plumbers came back today, drained and refilled. suggested coming back to re-do the flue which i think they didnt install correctly, and to replace the pump in case thats the issue. the water when it drained was really quite clear, so cant understand the problem - if there was sediment, i would have thought the water would be a bit mucky. he suggested that once it was drained and filled again next week, with the inhibitor added, it wouldnt be worth putting in the magnet - or at least to wait until then. ill put it in myself when theyve finished i think. 12 of the rads are not coming on, 7 are luke warm and 7 are piping hot at the moment.
How old are the radiators, can't believe there is no crud, every system will get a build up of crud over the years, I seen a system some years ago,water was clear, only because got to go part way around the system, the rest of system was blocked with crud. I would have put in some X800 first for a few weeks to run a round,also go around & tap radiators with a rubber mallet to loosen any crud, then drain. Trying taking one of the radiator not working off & go outside & run a hose through it.
ok good - that makes sense to me. i suppose given two and a half months to settle, it makes sense the **** would have settled well, and it would explain some radiators coming on, and then later not, and some partially working. the house i believe was built in the last 90s so the radiators are probably that old i would guess, 20 years?
Forums
Facebook
Twitter
You Tube
Instagram
Shop