When comparing hydronic systems designs that are common in North America with typical European equivalents, comparisons reveal details that would be beneficial in either market, but are not “traditional” in one market or the other.
Figure 1 shows a hydronic system that’s intended to supply four panel radiators, each with their own thermostatic radiator valve and an indirect water heater from a gas-fired sectional cast-iron boiler. The system is designed using primary/secondary piping. The primary circulator operates whenever the space heating load or the indirect water heater call for heat.
Single-stage non-modulating heat sources in zoned distribution systems often face short cycling, particularly with low thermal mass. When few zones are active, they struggle to dissipate generated heat quickly, causing temperature build-up and potential shutdown of the heat pump based on internal limits, with varied restart behavior depending on controls.
According to the 2025 Q3 Industry Report, Great Lakes = great radiant heating sales.
December 11, 2025
WarmlyYours reported strong third-quarter momentum, driven by a surge in Great Lakes radiant heating sales and steady gains across key product lines, signaling renewed stability in the broader housing and remodeling markets.
Mullady will spearhead the enhancement of business operations, customer service, and strategic positioning, driving MrPEX Systems towards achieving its goals.